It is customary for American genealogists to try to work their way back to the first immigrant in a family line. My first immigrant to the U.S. in the Robitall family line was Joseph Robitall, born in 1860, who came to Chicago in 1880 and married a lady named Philomene in 1882.
I got stuck there. However, I just got some help from Jean Robitaille of Quebec, who found records showing that my Joseph Robitall was Joseph Jean Robitaille, descendant of Pierre Robitaille de Champigny, the first North American immigrant in the line.
He was the son of Jean Robitaille de Champigny, born in 1625. His descendant jean Robitaille was able to acquaint me with nearly three centuries of additional family.