Jeannette was born on August 26, 1879, in West Hoboken, New Jersey, which is now part of Union City, to Mena and Benjamin F. Jeanette, who worked for a local blacksmith.

At 5 ft 10 in (1.78 m) and weighing 190 lb (86 kg), Jeanette was relatively short and stocky, with his initial knowledge of fighting stemming from youthful street brawls.

[3] Jeanette mimicked the style of Sam Langford, whom he fought 15 times (some sources say 14[4]), developing defensive techniques that were elusive and effective.

Because of the racial barrier, black boxers only had a small number of prospective opponents from which to choose, and often ended up matched against the same fighters over and over.

Jeanette criticized Johnson, saying, "Jack forgot about his old friends after he became champion and drew the color line against his own people.

After the 49th round, McVey could not rise from his stool at the call of time and Jeannette was declared winner on a technical knockout.

[9] A historical marker was subsequently dedicated at the corner of Summit Avenue and 27th Street, where Jeanette's former residence and gym once stood.

It was the first historical marker erected by the city, and was installed on April 17, 2009, the 100th anniversary of Jeannette’s 49th-round knockout of Sam McVea.