Hardy was born in Aberdeen, Mississippi, USA, near the border between Alabama and Mississippi, on 6 January 1894. He claimed to have been born in 1893, but the earliest document available to the GRG, the 1900 census, listed him as born in January 1894.

His parents, Morris and Nancy Hardy, were both born slaves (Morris was born in Texas in 1830, Nancy in Mississippi in 1849). They got married on 19 February 1868. The couple purchased a 274-acre farm near Aberdeen in 1874. Moses was the youngest of their nine children.

In the 1910s, he married Fannie Lou Marshall. Three months after his marriage, he was drafted and sent to Camp Funston, Kansas, and served in France in the 805th Pioneer Infantry for 39 days from July 1918 to July 1919. Hardy himself served as a scout, supplying the front line troops when necessary. Though Hardy did experience combat, he was never seriously injured and rarely discussed his experiences concerning the fighting. Instead, he preferred to recount stories about the food, the bravery of the soldiers and the weather in France.

Throughout the years, he received the Victory Medal, the Occupational Medal from the Mississippi Army National Guard, an honourable discharge (which he had not received upon leaving the army) and the French Légion d’honneur.

Although he suffered from mild dementia in his later years and had trouble speaking coherently, he was reported to have been completely lucid through his final days and his death was attributed to natural causes.

Hardy died in his hometown on 7 December 2006, at the age of 112 years, 335 days. He is the oldest validated man ever from the U.S. state of Mississippi.