From Dayton Ohio, Bill Mackey was born William Gretsinger Jr.. He started racing in AAA in 1949 at Springfield but failed to qualify the Dayton Coil Spring Special.
In 1950 he failed to qualify for the races at Syracuse and Detroit in September but in November he made the grid at Phoenix, qualifying in fifth spot. In teh race he finished 8th. He qualified again two weeks later at Bay Meadows, this time in 12 though once again crossing the line in eighth place. he finished the year with a crash at Darlington having qualified his Iddings Meyer Offy in fourth position he his the fence on lap 88
He made his one and only appearance at Indy in 1951, qualifying his Karl Hall Stevens Offy in 33rd place. In the race he went out with a broken clutch shaft after 97 laps. Two weeks later he raced at Milwaukee but spun out after 55 laps but then posted his best finish of fourth at Darlington on July 4th. Just over three weeks later he was killed in qualifying at the Winchester Speedway in Indiana, driving the Joe Langley Special in the AAA Sprint Car Championship. The track had only just been cleared from the wreckage of Cecil Green's accident in which he lost his life when Mackey crashed in the same place also loosing his life.