Pulaski, a Polish nobleman, was recruited by Benjamin Franklin in Paris in 1776. He arrived in Boston, in July 1777, after being lent passage money by American Ambassador Silas Deane. Pulaski saw his first action as a volunteer aide-de-camp to Washington at Brandywine on September 11. Even before that battle, Pulaski had informed Washington of his cavalry experience in Poland. Thus, Washington had written Congress on August 27th asking that Pulaski be put in charge of four regiments of dragoons which had recently been created. Congress instead created the post "Commander of the Horse," made Pulaski a Brigadier General, and elected him to the new position.
Naturally many American officers were incensed by Pulaski's new position. Even before the Pole had arrived, many battle-tested Continental officers were already disgusted with Congress for giving foreign adventurers ranks over theirs.
To make matters worse, this Pulaski spoke no English and reported directly to Congress. Initially, the new "Commander of the Horse" was loath to take orders even from General Washington.