Thanks for the resource -- I really like his work. A pair of Bradley Schmehl paintings flank an armoire in our den. I'd like more, but my wife wishes to reserve other wall space for more peaceful subjects.
Most 'unusual' uniforms date from early in the war or were provided by Federal quartermasters. The U.S. military had well-established procurement means and methods for almost anything of use in the army -- uniforms, arms, equipment, transportation, food. Sometimes we forget the importance of the existing U.S. military establishment to the Federal cause.
On the opposite side of the field, the Confederacy had to depend on makeshift resources, including private donations. For example, an acute shortage of modern military-grade weaponry to arm volunteers persisted from the second half of 1861 into the early months of 1862. Southern armories had been emptied, and arms shipments on order from agents in Europe had yet to arrive. Unless prospective officers could provide firearms for their recruits, the Secretary of War declined countless offers of new commands during this period. Many commanders made requests for pikes in order to arm their men.