Well a dictionary from that time would sure be helpful. Is 1755 close?
http://johnsonsdictionaryonline.com/?p=9727
MilÃtia. n.s. [Latin.] The trainbands; the standing force of a nation.
Let any prince think soberly of his forces, except his militia be good and valiant soldiers. Bacon's Essays, â„– 30.
The militia was so settled by law, that a sudden army could be drawn together. Clarendon.
Unnumbered spirits round thee fly,
The light militia of the lower sky. Pope's Rape of the Lock.
Johnson, Samuel. "Militia." A Dictionary of the English Language: A Digital Edition of the 1755 Classic by Samuel Johnson. Edited by Brandi Besalke. Last modified: January 5, 2013. http://johnsonsdictionaryonline.com/?p=9727.