Who is David ruggles? How does he help Douglass in New York?

Ruggles is a free black man who lives in New York City.  He takes Douglass in and helps Douglass' fiance join him.  Ruggles witnesses the ceremony between the two and gives Douglass so that they can go to New Bedford to find work.  He also give Douglass a letter of recommendation to help him find work once he gets there.