1830's
The cavalry in the US Civil War would usually dismount before they started a battle.
The US Cavalry.
In the US, prior to 1942, the US Cavalry was a mounted arm (horse units). It's missions were to exploit gaps made in enemy lines, conduct screening/security, and reconnaissance missions. The last US Horse Cavalry unit to fight from horse back was the US 26th Cavalry, which attacked Japanese light tanks in the Philippines during WWII in 1942. Congress officially de-activated (retired) the US Cavalry (Horse) in 1926. Post 1942, armor (tanks) have replaced the horse cavalry.
The US 26th Cavalry (Horse) fought the LAST "Horse Cavalry Action" (against Japanese tanks) in the Philippines in 1942. Congress no longer authorized the US Cavalry (Horse) at the end of '42.
cavalry
1936
The 7th Cavalry
1st Cav Div established in 1921. 1st Air Cav Div established in 1965. Or, stated in Army terms, 1st Cavalry Divison (Airmobile). The US Horse Cavalry was written off by Congress in '42 and replaced by the tank (Armor units). The last US horse cavalry fight was conducted by the US 26th Cavalry (Horse) in the Philippines in 1942...US horses verses Japanese Type 95 light tanks.
He is known as the Father of the US cavalry.
general custer
9th
Roosevelts' Cavalry Regiment was nicknamed the "Rough Riders". Officially, it was the First US Volunteer Cavalry Regiment (Army).