According to Wetzler's pension index card, he served in Cos. G and K, 37th Ill. Infantry Rgt., Co. G, 5th Corps de Afrique Infantry Rgt. which became the 77th U. S. Colored Infantry Rgt.
He is listed as a second lieutenant in the Official Army Register of the Volunteer
Force of the United States Army in 77th USCT Infantry and resigned April 13, 1864.
I assume he was commissioned in the 5th CdeA Infantry Rgt. when it was organized in December 1863.
This may explain why his Illinois record is incomplete

Morris applied for and received a pension (application #586106/certificate #360144)
Morris died Sept. 23, 1907 (no place given).
His widow Amalia (sic) applied for a pension on Jan. 13, 1911 while living in Missouri (application #956033/certificate #729772)