I don't know the strength of the regiment. As to their participation in the battle of Nashville, that reference comes from the short history of the regiment in Dyer's Compendium. Dyer was incorrect as far as their participation in the battle at Nashville (December 15-16, 1864) is concerned. They had been ordered from Missouri to Nashville, but were still in transit when the battle was fought. The 45th was on duty in late December at Nashville and at Spring Hill, but were ordered back to Missouri in late January, 1865. The 45th was enlisted for 6 months, and were ordered back to Missouri near the end of that 6 month enlistment.