The term "requisitioned" or "requisition" in use with State Militias, is found in more numbers in the O.R. in reference to a presidential call to the governors of States for their militias. His statement is vague and seems to be pointed to the subject of combat...

"they were ready to fight for us if we had brought them into requisition"

Now, guard duty and police work is not considered combat, and militia can be called up for those duties. Being that these "Native Guard" units were primarily a New Orleans group, ill equipped, and contraversial for serving outside of New Orleans, they may have been only looked upon to perform duties within the city--- a city militia--- not uncommon. That could explain why they were left in New Orleans. And the possibility that they were on call and organized for the defence of the city is still there. New Orleans was never attacked so they never fought.

David