From WikiPedia: http://en.wikipedia.org/wiki/Casimir_Pulaski
After arriving in America, Pulaski wrote to Washington, "I came here, where freedom is being defended, to serve it, and to live or die for it."[
His first military engagement against the British was on September 11, 1777, at the Battle of Brandywine. When the Continental troops began to yield, he reconnoitered with Washington's bodyguard, and reported that the enemy were endeavoring to cut off the line of retreat. He was authorized to collect as many of the scattered troops as came in his way, and employ them according to his discretion, which he did in a manner so prompt as to effect important aid in the retreat of the army.[11] His courageous charge averted a disastrous defeat of the American cavalry and saved the life of Washington.[13] As a result, on September 15, 1777, Washington promoted Pulaski to brigadier general of the American cavalry.[12]