What does it mean if a soldier was listed as an New Unassigned York Infantry for the civil war?

My guess would be that the man had recently been drafted, or volunteered, and had not yet been assigned to one of the New York infantry regiments (of which there were more than one hundred). Volunteers usually joined a specific regiment, though by the latter half of the war, when many were joining northern units for the large bounty money offered, they might have been assigned to whichever regiment was most in need, rather than the one they wanted to be in with their friends, neighbors and relatives.