Well a dictionary from that time would sure be helpful. Is 1755 close?
Milítia. 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, № 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