Shell became the first African-American head coach in the modern N.F.L. For Shelmon, now the offensive coordinator for the San Diego Chargers, Shell’s hiring opened up possibilities he had dreamed of but never seriously imagined while growing up in Bossier City, La., in the 1950s.
For many aspiring African-American coaches, becoming a head coach in the N.F.L. seemed an insurmountable mountain.
