In early 1920, Okeh Records planned to record popular singer Sophie Tucker performing a pair of songs by songwirter Perry Bradford. Tucker was ill and could not make it to the session; Bradford persuaded Okeh to allow Mamie Smith to record in Tucker's place. Smith recorded two sides ("That Thing Called Love" and "You Can't Keep A Good Man Down") on February 14, 1920, backed by a white studio band. Smith's record sold moderately well, so she and Bradford were invited back to make additional recordings. On August 10 of 1920, Smith recorded "Crazy Blues" and "It's Right Here For You, If You Don't Get It, 'Tain't No Fault of Mine". This record became an explosive best seller. To the surprise of record companies, large numbers of the record were purchased by African-Americans, a market the record industry had hitherto neglected. "Crazy Blues" in particular was noted as a distinctively "colored" number performed by a "colored" performer. Although other African Americans had been recorded earlier (going back to George W. Johnson in the 1890s), they were all black artists who had a substantial following with white audiences. Mamie Smith opened up the record industry to recordings by and for African Americans.
Mamie Smith continued to make a series of popular recordings for Okeh throughout the 1920s. She also made some records for Victor. She toured the United States and Europe with her band "Mamie Smith & Her Jazz Hounds" as part of "Mamie Smith's Struttin' Along Review". She was billed as "The Queen of the Blues". (Shortly later, this billing of Mamie Smith was one-upped by Bessie Smith, who called herself "The Empress of the Blues".)
Mamie Smith appeared in an early soundie, Jail House Blues, in 1929. She retired from recording and performing in 1931. She returned to performing in 1939 to appear in the motion picture Paradise in Harlem. She appeared in further films, including Mystery in Swing, Sunday Sinners (1940), Stolen Paradise, Murder on Lenox Avenue (1941), and Because I Love You (1943).