The timeline on his record would suggest yes, he was. However the "Company S" part is a little odd to me. The 1st Md. Cav. had 11 original Companies and added Company M after Gettysburg. I'd check a little further to verify "Company S". There's a monument to the 1st MD.Cav. East of Gettysburg near the cavalry field, the Reg. most definitly took part in the action on the 2nd and 3rd day I believe.
p.s. Theres an image of him posted on Pinterest, looks like its for sale in e-bay. Not sure if you're aware.