What did friedrick von steuben achieve with the continental army?

He restored the morale of the Continental Army in addition to introducing discipline and putting the tattered soldiers into fighting shape. He drilled the troops which were often in bad shape and defeated which was vital in helping the Continental Army accomplish its missions.

the answer to your question is a. the salt plains

in 1811, he led an expedition, known as the george c. sibley expedition, to improve relations with the pawnee and kansa tribes, and also to locate the rumored jefferson's salt mountain

c) troops march forward in close formation against newer, more accurate weapons