At the time of his death at age 64, he attained the rank of Police Inspector, and during his career received the NYPD's Medal of Valor twice.

During his competitive years he stood 5′ 11½″ (1.82 m) tall and weighed 247 lb (112 kg), and was part of a group of large and dominant throwers referred to as the Irish Whales.

He remained in the world's top ten up to the age of 50, making his career one of the longest and most consistent in the history of the sport.

At the 1920 Olympics McGrath was a co-favorite along with fellow Irish American Athletic Club member Patrick Ryan, but finished fifth after injuring his knee during the competition.

There was a public outcry over McGrath's omission from the team and although he went to Amsterdam after a subscription fund had been raised to pay for his transportation, he was, not surprisingly, not allowed to compete.