[3] On August 4, 1915, he assumed command of the 15th Company, 2nd Regiment, Port-au-Prince, Haiti,[4] where he participated in engagements against Haitian rebels known as cacos.

[5] When the United States entered World War I in April 1917, he was again detailed for foreign shore duty, this time with the 13th Regiment in France from September 1918 to August 1919, during which time he was in command of the American Military Prison, Casino des Lilas, Bordeaux and the American Guard Camp.

[3] His last station of duty was that of the Department of the Pacific, where he served as commanding general with headquarters in San Francisco, California, from January 1, 1942, until the time of his death.

In September 1948, his remains were removed from his Alaskan burial plot and reinterred at the United States Naval Academy at Annapolis, Maryland.

After dark on the evening of 24 October 1915, while crossing the river in a deep ravine, the detachment was suddenly fired upon from three sides by about 400 Cacos concealed in bushes about 100 yards from the fort.

The marine detachment fought its way forward to a good position, which it maintained during the night, although subjected to a continuous fire from the Cacos.

Upshur, in command of the three squads which advanced in three different directions, led his men forward, surprising and scattering the Cacos, and aiding the capture of Fort Dipitie.