1904 Republican National Convention - Wikipedia

On June 21, 1904, "the US Republican Party nominates Theodore Roosevelt for President, but not without opposition from those whom he calls 'malefactors of great wealth.'" From the article:

"The popular President Theodore Roosevelt had easily ensured himself of the nomination, though a threat had come from the Old Guard favourite Ohio Senator Mark Hanna, the loyal kingmaker in Republican politics. But the senator had died early in 1904 therefore ending all opposition in the Republican Party.

There were also very informal talks with future president William Howard Taft about trying for the nomination, but Taft refused these motions as evidenced by a letter to Henry Hoyt, the Solicitor General, in 1903.

Roosevelt was nominated by 994 votes to none. The other threat to Roosevelt, Indiana Senator Charles W. Fairbanks was nominated for Vice President.

Platform

Speaker of the House Joseph Gurney Cannon at the convention.
The 1904 Republican platform favored the protective tariff, increased foreign trade, the gold standard, expansion of the Merchant Marine and strengthening of the United States Navy; it also praised Roosevelt's foreign and domestic policies.

Vice Presidential candidates
Vice President Roosevelt had ascended to the presidency in 1901 after the death of President William McKinley. As the 25th Amendment had not yet been passed, there was no way to fill the vice presidential vacancy. So the 1904 convention had the task of choosing a new running mate for Roosevelt. Entering the convention, Senator Charles Fairbanks of Indiana was considered the likely favorite for the vice presidential nomination, but the Roosevelt administration favored Illinois Congressman Robert R. Hitt or Secretary of War William Howard Taft of Ohio.[1] Speaker Joseph Gurney Cannon of Illinois also had support among the delegates, but Cannon had no desire to leave his position in the House.[1] However, the administration did not launch a fight over the nomination of Fairbanks, and Fairbanks was nominated by acclamation.[2]"