I will add to this answer on the EMM--In an opinion of the US Attorney General of Sept. 28, 1878, it was concluded that the Enrolled Missouri Militia "did not constitute a part of the Army of the United States but were a force acting from time to time in cooperation with it" in addition "the order disbanding such troops cannot be considered the equivalent of an honorable discharge in the sense that those words are used in Section 2304, Revised Statutes." See Missouri Troops in Service During the Civil War--Letter from the Secretary of War.... Washington 1902. Some exceptions exist, notably three companies of the First Regiment and four companies of the 63rd Regiment which were mustered into the US Service in 1864.
I believe that many in the EMM applied for pensions when they saw other EMM men who served in the Provisional Enrolled Missouri Militia being approved, following a change in the Law June 27, 1890. It is ironic that some men who gave but little service in the Pr. EMM got a pension while some who served many months in the EMM were ineligible. This was made that much worse when EMM were killed in the line of duty. In a possibly unique case, I discovered that a man who served in the 32nd EMM was given a pension based on EMM service by a Special Act of the 56th US Congress, May 18, 1900. Surely other exceptions exist.