Now, to confuse everyone! In August, 1861, the old 1st and 2nd Dragoon Regiments became the 1st and 2nd Cavalry Regiments.
The 3rd Cavalry became the Sixth Cavalry and the old Regiment of Riflemen became the new 3rd Cavalry. Then, to add to your
confusion, the previous 1st and 2nd Cavalry Regiments became, respectively the 4th and 5th Cavalry Regiments.
"Who's on first?". I mention all this so anyone interested in antebellum Regular regiments will understand that the "old"
units were not the same as during the War of the Rebellion. And no, Lee never served at Fort Gibson nor his 2nd Cavalry.