Vraciu was born in East Chicago, Indiana, on November 2, 1918, the second child and only son of Alexandru Sr. and Maria (née Tincu) Vraciu. Vraciu's parents immigrated from Transylvania, Romania at the turn of the century, settling in East Chicago, where they met and were married. (His father was born in Poiana Sibiului, and his mother was from Sebeș.) When Alex was seven or eight years old, the family traveled to Transylvania (Romania) for a brief residence. His parents hoped that the experience would immerse their children in the culture. Afterward, the family returned to Indiana, where Vraciu resumed his education, graduating from East Chicago's Washington High School in 1937.