Armstrong was born on August 4, 1901, into a poverty-ridden section of New Orleans nicknamed “the Battlefield.” His father abandoned the family when Armstrong was a child, and his teenaged mother was often forced to resort to prostitution to make ends meet. Young Louis spent much of his boyhood in the care of his grandmother, but he also found a second home among the Karnofskys, a local Lithuanian-Jewish family who hired him to do odd jobs for their peddling business. The jazzman would later write that the Karnofskys treated him as though he were their own child, often giving him food and even loaning him money to buy his first instrument, a $5 cornet (he wouldn’t begin playing the trumpet until 1926). As a sign of his gratitude to his Jewish benefactors, Armstrong later took to wearing a Star of David pendant around his neck.

Armstrong spent his youth singing on the street for spare change, but he didn’t receive any formal musical training until age 11, when he was arrested for firing a pistol in the street during a New Year’s Eve celebration. The crime earned him a stint in a detention facility called the Colored Waif’s Home for Boys, and it was there that Armstrong claimed, “me and music got married.” He spent his 18-month sentence learning how to play bugle and cornet from the Waif’s Home’s music teacher, Peter Davis, and eventually became a star performer in its brass band. Armstrong continued honing his skills in New Orleans’ honkytonks after his release, and in 1919, he landed a breakthrough gig with a riverboat band led by musician Fate Marable. “I do believe that my whole success goes back to that time I was arrested as a wayward boy,” he later wrote, “because then I had to quit running around and began to learn something. Most of all, I began to learn music.”

Armstrong’s hesitancy to speak out against racism was a frequent bone of contention with his fellow black entertainers, some of whom branded him an “Uncle Tom.” In 1957, however, he famously let loose over segregation. At the time, a group of black students known as the “Little Rock Nine” were being prevented from attending an all-white high school in Arkansas. When asked about the crisis in an interview, Armstrong replied, “The way they are treating my people in the South, the government can go to hell.” He added that President Dwight D. Eisenhower was “two-faced” and had “no guts” for not stepping in, and declared that he would no longer play a U.S. government-sponsored tour of the Soviet Union.

The comments caused a sensation in the media. Some whites even called for boycotts of the trumpeter’s shows, but the controversy soon blew over after Eisenhower sent soldiers to desegregate the schools in Little Rock. “I feel the downtrodden situation the same as any other Negro,” Armstrong later said of his decision to speak out. “I think I have a right to get sore and say something about it.”