Undefeated at that point, Sullivan did not defend his title for the next four years.
 During this period, he was a friend and supporter of Irish boxer Ike Weir, who became America's first Featherweight boxing champion in 1889.
 Both Weir and Sullivan were Boston natives, and Sullivan occasionally appeared at Weir's bouts.

Sullivan agreed to defend his title in 1892, against challenger "Gentleman Jim" Corbett.
 The match was on 7 September in New Orleans.
 It began at 9 p.m. in the electrically illuminated Olympic Club in the upper Ninth Ward neighborhood now known as Bywater section.
The venue filled to its 10,000 person capacity despite hefty ticket prices ranging from $5 to $15 (approximately $142 to $426 in 2020).
 The heavyweight contest occurred under the Marquess of Queensberry Rules, but it was neither the first title fight under those rules nor was it the first title fight using boxing gloves.
Corbett was younger and faster, and his boxing technique enabled him to dodge Sullivan's crouch and rush style.
 In the 21st round, Corbett landed a smashing left "audible throughout the house" that put Sullivan down for good.
Sullivan was counted out and Corbett was then declared the new champion.
 When Sullivan was able to get back to his feet, he announced to the crowd the following: "If I had to get licked, I'm glad I was licked by an American".

Sullivan is considered the last bare-knuckle champion because no champion after him fought bare-knuckled.
However, Sullivan had fought with gloves under the Marquess of Queensberry Rules as early as 1880 and he only fought bare knuckle three times in his entire career (Ryan 1882, Mitchell 1888, and Kilrain 1889).
His bare-knuckle image was created because both his infrequent fights from 1888 up to the Corbett fight in 1892 had been bare-knuckle.

Sullivan retired to Abington, Massachusetts but appeared in several exhibitions over the next 12 years, including a three-rounder against Tom Sharkey and a final two-rounder against Jim McCormick in 1905 in Grand Rapids, Michigan.
He continued his various careers outside boxing such as being a stage actor, speaker, celebrity baseball umpire, sports reporter, and bar owner.
In his later years, Sullivan also gave up his lifelong addiction to alcohol and became a prohibition lecturer.
Undefeated at that point, Sullivan did not defend his title for the next four years.  During this period, he was a friend and supporter of Irish boxer Ike Weir, who became America's first Featherweight boxing champion in 1889.  Both Weir and Sullivan were Boston natives, and Sullivan occasionally appeared at Weir's bouts.
Sullivan agreed to defend his title in 1892, against challenger "Gentleman Jim" Corbett.  The match was on 7 September in New Orleans.  It began at 9 p.m. in the electrically illuminated Olympic Club in the upper Ninth Ward neighborhood now known as Bywater section. The venue filled to its 10,000 person capacity despite hefty ticket prices ranging from $5 to $15 (approximately $142 to $426 in 2020).  The heavyweight contest occurred under the Marquess of Queensberry Rules, but it was neither the first title fight under those rules nor was it the first title fight using boxing gloves. Corbett was younger and faster, and his boxing technique enabled him to dodge Sullivan's crouch and rush style.  In the 21st round, Corbett landed a smashing left "audible throughout the house" that put Sullivan down for good. Sullivan was counted out and Corbett was then declared the new champion.  When Sullivan was able to get back to his feet, he announced to the crowd the following: "If I had to get licked, I'm glad I was licked by an American".
Sullivan is considered the last bare-knuckle champion because no champion after him fought bare-knuckled. However, Sullivan had fought with gloves under the Marquess of Queensberry Rules as early as 1880 and he only fought bare knuckle three times in his entire career (Ryan 1882, Mitchell 1888, and Kilrain 1889). His bare-knuckle image was created because both his infrequent fights from 1888 up to the Corbett fight in 1892 had been bare-knuckle.
Sullivan retired to Abington, Massachusetts but appeared in several exhibitions over the next 12 years, including a three-rounder against Tom Sharkey and a final two-rounder against Jim McCormick in 1905 in Grand Rapids, Michigan. He continued his various careers outside boxing such as being a stage actor, speaker, celebrity baseball umpire, sports reporter, and bar owner. In his later years, Sullivan also gave up his lifelong addiction to alcohol and became a prohibition lecturer.
John L. Sullivan