Short answers, pulled from the story.
Charles Follis began receiving pay for playing football in 1899. He played for the Shelby Blues from 1902 until 1906 and marks the earliest known instance of a black professional football player earning money for his athletic skills.
By 1934 no black players remained in the National Football League due to an informal agreement among owners that kept them out through 1945. George Preston Marshall became the chief instigator of segregation within the league by refusing to sign any black athletes to his Boston Braves or Washington Redskins teams.
The Los Angeles Rams signed Kenny Washington on the 21st of March 1946 after legal threats regarding public stadium funding. Members of the African American print media reminded the Los Angeles Coliseum commission that the NFL had no African American players and pointed out that the stadium was supported by public funds.
In Week One of the 2020 season ten quarterbacks with known Black African ancestry started games including Cam Newton Teddy Bridgewater Lamar Jackson and Patrick Mahomes. Marlin Briscoe became the first black regular starting quarterback of the modern era while playing for the Denver Broncos in the American Football League.
Art Shell became the first black head coach in the NFL since the player-coach era ended in 1989 when he took over the Los Angeles Raiders. An affirmative action policy called the Rooney Rule implemented in 2003 required teams to interview racial minorities for head coaching roles.