Springfield M1795
During WW1 bolt action rifles were the main weapons used on the battle field.
The American weapon of choice was the Springfield M1795 which later became the M1903 which accumulated a 50 year service recored as a variety of rifle platforms.
The Bolt action platform was easy to use but had a slow rate of fire. This was because when the rifle was fired the user had to manually chamber the next round. They generally had 3 to 5 round spring loaded magazines. Because of the slow rate of fire and the limited magazine capacity they only worked when firing across no-mans land and operated poorly in the close quarters of the trenches.
Vickers Machine Gun and The BAR
The opening debut for the machine gun platform came during the first world war. The machine gun became the lethal enemy of the horse brigades of the first world war. With such a high rate of fire compared to the bolt action rifles of the time. However the guns were big and clunky as well as water fed, they also required a 3 ma team to move and operate, making moving them in the heat of battle a deadly but necessary idea. Luckily in the final year of the war Browning came out with the BAR (Browning Automatic Rifle). This was a smaller lighter gun, that was able to be moved around the battle field by one man giving America a deadly edge.
Colt M1911
This was the standard issue pistol of the United States Army and Navy (Pilots were not expected to need a pistol for generally if they crashed they also died) The Colt was a semi automatic magazine fed pistol that held up to 7 rounds. It was chambered with the deadly .45 caliber round. It unlike the bolt action rifles of the time was perfectly suited to the close quarters of the trenches. This is due to the large caliber that was able to inflict grievous wounds that would incapacitate or kill the enemy instantly.
M3 Trench Knife
This is the favored knife of the United states soldiers in the trenches. It has a full tang with a brass hilt and a normally leather covered wood handle that offered a sturdier grip when thrusting or slashing. It was useful in the trenches to use in unison with a pistol.