Eisner Original

Ebony became The Spirit's first and most loyal partner. He was a taxi driver that encountered Denny Colt's alter ego while driving Ellen Dolan and Homer Creep past Wildwood Cemetery.  Ebony was an intelligent person but spoke with a heavy accent that later caused controversy over racial stereotypes (Will Eisner was always deeply found of the character).

It seemed that Ebony did not have any family of his own and lived in Wildwood Cemetery with the Spirit.  After much criticism over the stereotypes of the character, Eisner decided to have Ebony shipped off to school in the February 10, 1946 strip. That wasn't the end of Ebony though. He did continue to make several more appearances  throughout the rest of the series. 
 
As the Spirit's sidekick Ebony fought crime with him at his side.  He was very skilled despite his being depicted as a  bad stereotype.  He was even a skilled pilot and flew the Autoplane on various missions for the Spirit.

Modern Age Ebony

In the DC comics reboot started by Darwyn Cooke, Ebony was heavily revamped into a much more intelligent and streetwise character. He operates a taxicab during the night but it is implied that he stole it.  He acts as the Spirit's getaway driver and his occasional sidekick. In this version Ebony is very well read.  He also appears to be either a runaway or at least has no real home to speak of.
  

First Wave

This version is probably the most dramatically different, in that in the world of First Wave, Ebony is a teenage girl.