Hi Eric, The pension file of my relative, Reubin Bryant (available in full on Fold3) states that he was a private in Capt. McCrae's company, 20th US Regiment of Infantry. It also states that he enlisted 17 June 1812-17 Dec 1813. Reubin lived in north central Buckingham Co, very close to the James River.
You stated in another message that Capt. McRae was not attached to the 20th Regiment. Was there another captain with a similar name?
I looked at the October roster at the newrivernotes website and Reubin was not listed.