Why do modern day Marines carry a sword? - Quora

Tradition: Marine Corps history states that a sword of this type was presented to Marine First Lieutenant Presley O'Bannon by the Ottoman Empire viceroy, Prince Hamet, on December 8, 1805, during the First Barbary War, in Libya, as a gesture of respect and praise for the Marines' actions at the Battle of Derna (1805), the Mameluke Sword. NCO sword was commissioned in 1859. Both are part of the dress and parade uniform.