What was the most significant event on April 3 during the U.S. Civil War 2017 update?

In April 1861 Fort Sumter, South Carolina was in peril. By April 1865 the CSA President, cabinet and staff had fled their capital of Richmond, Virginia and arrived in Danville, Virginia.
In 1861, some vessels at sea were unaware that southern states were rebelling or that Fort Sumter was being besieged. The captain of the Boston-home-port vessel Rhoda H. Shannon was making his way to Charleston, SC when CSA batteries began to fire across his bow. [details below]
In 1863, ironically the Confederate governor of Arkansas supported centralized government of Richmond more than states’ rights.
In 1865. fighting would continue in other parts of the Confederacy as news traveled slowly and some decided not to concede even though the CSA President and many military commanders had surrendered.
Many were honorable but some became bandits. In any event, nobody desires to be the last soldier killed in a conflict or to be killed after the war has been ended.
Wednesday, April 3, 1861: The unhappy story of the Rhoda H. Shannon. “Major Anderson was nearly out of supplies. His command was receiving some dwindling amount from Charleston, but that appeared to be tapering off. He wrote to Washington asking yet again for instructions. Was he to be starved out? What was he to do once his provisions were exhausted? [1]
But then, for a moment, he thought he might have his answer.
At half-past two in the afternoon, a guard ran into the mess hall. A schooner flying the stars and stripes was in the harbor! The Confederate batteries on Morris Island had her under fire!
Anderson immediately ordered several guns to be readied.
Captain Joseph Marts, skipper of the Rhoda H. Shannon, a private ship out of Boston, hardly followed the news. He had heard of some trouble in Charleston and maybe something of a few Southern states making their own nation, but rumors and nothing more than that.
What he did know was that the Rhoda H. Shannon had a 180-tons of rice to deliver to Savannah. What he thought he knew was that he had arrived at his destination. Charleston’s lighthouse guided him into what he believed was Tybee Roads, off Savannah.
Marts believed he saw a pilot boat waiting to guide him to the docks. Ignorantly, he ran up the United States flag in the fore rigging as a signal to be lead ashore. Seeing no response after a few minutes, he began to bring his vessel into the harbor.
He guided the schooner past what he believed to be Tybee Island, but was actually Morris Island, where, unknown to him, multitudes of heavy artillery were pointed directly at the Rhoda H. Shannon.
A shot rang out from the island and a ball streaked across the sky and over his bow.
Whispers of a possible attempt to resupply Fort Sumter had been in the air as much as the rumors of surrender. The Confederate officers expected Sumter’s reinforcement as much as they expected its abandonment.
When the Confederate gunners saw an unidentified ship, flying no colors, passing before Morris Island to enter the main ship channel, a mile away from Fort Sumter, they followed orders (and tradition) to fire a single shot over the bow of the ship.
Marts took this shot as a warning to show his colors. Following these suspected orders, the stars and stripes were run up to his gaff peak. The Confederates, having also the orders to fire upon any ship flying those colors, lobbed several more shots over her bow.
Captain Marts had no idea what they wanted or what to do. He would continue on his course.
Marts, the unfortunate schooner’s captain lowered his colors and continued on his way. The firing continued as well. None of the shots struck his vessel, but when one ball tore through the mainsail, passing just two feet from the boom, he turned her about to put out to sea.
Even with this “retreat,” at least one battery continued to fire upon him until he was out of their range. He anchored in the Swash Channel, away from Morris Island, but just inside the bar.
Captain Marts welcomed a small boat sent from the nearby Fort Sumter by Major Anderson, needing to know what the ship was about and why she was fired upon. The men from Sumter gathered information and informed the Captain exactly where he was.
The ship was in some rough water, so they advised him to either anchor farther out to sea or continue on to Savannah.
Having enough, Captain Marts took the Rhoda H. Shannon and guided her back out to sea, wanting nothing more to do with whatever was going on in Charleston. [2]
[1] Official Records, Series I, Vol. 1, p234.
[2] Official Records, Series I, Vol. 1, p236 – 240. Some help was given by Allegiance by David Detzer, who had access to a few sources I did not. However, the bulk of this story comes from the Official Records.
http://civilwardailygazette.com/the-unhappy-story-of-the-rhoda-h-shannon/
Friday, April 3, 1863: Unable to feed the hungry in Richmond, Jefferson Davis tried to reassure Arkansas. “While the women of Richmond again threatened to protest and riot over food shortages in the city, President Jefferson Davis turned to matters he could better understand: the importance of the Mississippi River. At the start of the war, the South controlled (or at least had access to) pretty much the entire stretch from Cairo, Illinois south to New Orleans and the Gulf of Mexico. Two years later, all that was left was Port Hudson and Vicksburg, both on the eastern bank.
That is not to say that Confederate forces didn’t have some control over other portions on the western bank. The Red River, including Fort Taylor, for example, was wide open (though Union Admiral Farrugut was threatening to blockade it).
With this in mind, President Davis took up his pen and wrote to Arkansas Governor Harris Flanagin. Governor Flanagin was a Northern by birth. He grew up in New Jersey, attending a Quaker school before moving to Pennsylvania, where he became a mathematics professor. In Illinois, he established his own school and soon after became a lawyer. For the two decades prior to the war, however, he lived in Arkansas, where he entered politics. That only lasted till the early 1850s, when he gave it up for a more local home life.
When the war broke out, he was, at first, a Unionist, but when Arkansas seceded, he did as well, and joined the Confederate army. Following the battles of Wilson’s Creek and Pea Ridge, he was promoted to colonel of an Arkansas Mounted Regiment. A year later, while serving in the Army of Tennessee, he was nominated for the position of Arkansas’ Governor. He surprisingly won, beating out incumbent, Henry Massie Rector, who was threatening to secede from the Confederacy.
What really set him apart from the previous governor was that he was completely fine with Richmond’s usurpation of states rights. He did not oppose the draft, and, like Davis, was in favor of a strong central government.
He had written Davis on January 5th, but the President could not find the time to reply until this date, three months later. “The defense of the Mississippi River on both banks has been considered by me as of primary importance,” wrote Davis, “and I can assure you that you cannot estimate more highly than I do the necessity of maintaining an unobstructed communication between the States that are separated by the river.” This necessity for “unobstructed communication,” of course, didn’t mean that Arkansas would always get a timely reply.
Davis then went on to explain his strategy for keeping the Mississippi open, deeming Port Hudson and Vicksburg indispensable. “If we succeed, as I have confidence we shall, in maintaining these two positions,” continued Davis, assuming quite a lot, “we preserve the ability to furnish the munitions and ordnance stores necessary for the supply of the troops on the west bank, and to throw across the river adequate forces for meeting the enemy, if he should transfer his campaign from Tennessee, Mississippi, and Alabama to Arkansas and Louisiana.”
Davis figured that since Port Hudson and Vicksburg could not be taken by the Federals, they would next invade Arkansas and Louisiana. Governor Flanagin had requested more troops, specifically those from Arkansas and Missouri, to be sent back to his state, where the Confederates were greatly outnumbered.
The President responded, telling him that “we are sadly outnumbered on all our lines of defense.” Nevertheless, “it will be found that the disproportion between the opposing forces has been more largely against us on the eastern than on the western side.”
…
When Flanagin wrote Davis in January, he asserted that there were only forty regiments in the entire state. Davis, with new information at hand, had to break the news that actually the number was quite a bit closer to twenty-four. He tried to soften the blow by telling him that the numbers might be a bit off if one took into account Arkansas troops from regiments sent to other states that had deserted and fled back to their homes, quite possibly joining up with other Arkansas Regiments. but probably not.
What this all boiled down to was Flanagin’s (and others’) complaints that Arkansas and Missouri troops were being taken out of their home state to fight elsewhere. “Our safety, our very existence,” expounded Davis, “depends on the complete blending of the military strength of all the States into one united body that is to be used anywhere, everywhere, as the exigencies of the contest may require for the good of the whole.”
Flanagin, being a supporter of a more centralized government, probably understood this well. There had been pressure from Arkansas politicians to push this agenda with Richmond. Still, Davis explained the philosophy behind it: “The discipline and efficiency of our armies have been found to be far greater when the troops were separated from their homes, and thus delivered from the constant temptation to absent themselves from duty presented by proximity to their families.” It was almost like Davis was admitting that many of the soldiers didn’t support the cause.
In closing, Davis assured him that he would make an effort to make sure there were enough troops “to protect your State to the utmost extent of our ability.” He reminded him of the recent command change placing General Kirby Smith at the head of the Department of the Trans-Mississippi, and hoped it would have a “good effect in satisfying the good people of your State, and supplies of arms and munitions will be constantly forwarded as rapidly as our resources and means of transportation will permit.” [1]
[1] Sources: The Confederate Governors edited by Buck Yearns; Official Records, Series 1, Vol. 53, p865-866.
http://civilwardailygazette.com/unable-to-feed-the-hungry-davis-tries-to-reassure-arkansas/

Pictures: 1861-04-03 Approach to Fort Sumter by the Rhoda H. Shannon map; 1865-04-03 in Petersburg, Lincoln met Grant for the final time during the campaign at the Wallace House; 1865-04-03 Union Troops enter Richmond VA Leslie's Illustrated; 1865-04-03 US officers scrambled to the top of the Confederate state house–a building designed by Thomas Jefferson–and raised the Stars and Stripes atop the building. The officer responsible, Johnson de Peyster, hailed from New York

A. 1862: CSA Gen A.S. Johnson and Maj Gen U.S. Grant converge their forces towards Shiloh Church, [alternately known as Pittsburg Landing] Tennessee. CSA Gen. Albert Sidney Johnston had planned to piecemeal defeat the Union forces before the various Union units in Kentucky and Tennessee consolidated. U.S. Grant had 40,000 men at Pittsburg Landing, Tennessee, and Maj. Gen. Don Carlos Buell was on his way from Nashville with 35,000 men. Johnston started his army in motion on April 3, 1862, intent on surprising Grant's force as soon as the next day, but they moved slowly due to their inexperience, bad roads and lack of adequate staff planning. Due to the delays, as well as several contacts with the enemy, Johnston's second in command, P. G. T. Beauregard, felt the element of surprise had been lost and recommended calling off the attack.
B. 1863: Engagement at Snow Hill, Tennessee. A Union detachment of 1,500 infantry and cavalry, commanded by Brig. Gen. David S. Stanley, was sent on a scouting expedition toward the area of Snow Hill. The Confederate force in the area was commanded by Col. Richard M. Gano. Gano learned of the Union approach and stationed his men at Snow's Hill. Snow's Hill was a series of level-topped ridges and deep ravines sloping westward from a plateau into the valley where Liberty was located. Gano deployed his 2 brigades in a defensive line midway down the ridges.
At daylight, Stanley fired on the Confederate line with his artillery. This had a devastating effect on the Confederates. Next, the Union infantry charged the Confederate line while the Union cavalry advanced up a dry creek bed on the Confederate left flank. Surrounded, the Confederate force was soon routed.
C. 1864: Major General Banks began his preliminary deployments for the Red River campaign, ironclads USS Eastport, USS Mound City, USS Osage, USS Ozark, USS Neosho, USS Chillicothe, USS Pittsburgh, and USS Louisville and steamers USS Fort Hindman, USS Lexington, and USS Cricket convoyed Major General A. J. Smith’s corps from Alexandria to Grand Ecore, Louisiana. The troops disembarked (with the exception of a division under Brigadier General T. Kilby Smith) and marched to join banks at Natchitoches for the overland assault on Shreveport, to be supported by ships of the Mississippi Squadron.
D. 1865: The US flag is flown over the towns of Petersburg and Richmond, Virginia, by the Union forces. It is made official that Brig. General Godfrey Weitzel and the Army of the James formally accepted the city of Richmond’s surrender. Meanwhile, Confederate President Davis and his cabinet arrived in Danville, Virginia.
The Union cavalry entered Richmond. By 7:15 Monday morning, April 3, two guidons of the Fourth Massachusetts Cavalry flew over the capitol building. Not long after, two officers of the 13th New York Artillery took down the little triangular flags and ran up the great United States flag. Union General Godfrey Weitzel sent a telegram to General Grant: "We took Richmond at 8:15 this morning. I captured many guns. The enemy left in great haste. The city is on fire in two places. Am making every effort to put it out. The people received us with enthusiastic expressions of joy."
Weitzel ordered his troops to put out the fire. The city's two fire engines worked, bucket brigades were formed. Threatened buildings were pulled down to create firebreaks. Five hours later the wind finally shifted, and they began to bring it under control. All or part of at least 54 blocks were destroyed, according to Furgurson. Weitzel wrote "The rebel capitol, fired by men placed in it to defend it, was saved from total destruction by soldiers of the United States, who had taken possession." And the city rested