His death was confirmed by the US company.

“He was the heart and soul of FedEx – its PSP culture, values, integrity, and spirit.

“He was a mentor to many and a source of inspiration to all.”

Smith originally conceived the concept for FedEx during his time at Yale University, where he penned a term paper outlining an innovative approach to transporting time-sensitive packages.

He famously received only an average grade on the paper.

In 1971, he established the company under the name Federal Express in Little Rock, Arkansas. The business took off in Memphis two years afterward, staffed by 389 employees operating 14 aircraft to deliver 186 packages to 25 cities across the United States.

The company grew steadily over the next 50 years, buying its first seven Boeing 727s freighters after two years of lobbying led to Congress deregulating air cargo.

It also bought a series of other companies to help it grow, both internationally and with ground services in the US, creating both a FedEx Ground unit that moved most of its goods by truck and delivery vans and FedEx Freight, which handled pallet-sized shipments of freight by truck.

And it also bought Kinko’s copier centers and rebranded them as FedEx Office locations.

“We were a small startup and had our share of sceptics. But that first night of operations set into motion what would become a global connector of people and possibilities that would change our world for the better,” Smith said in a letter to FedEx employees announcing his retirement as CEO in 2022.

After stepping down as CEO, Smith continued to serve as FedEx’s executive chairman.

Born in 1944 in Marks, Mississippi, Smith served for four years in the US Marines.

After two tours of duty in Vietnam, Smith returned to start his company, which grew to a nearly $US90 billion ($139 billion) global shipping empire across 220 countries and territories.

Former President George W. Bush called Smith “one of the finest Americans of our generation” in a statement on Sunday.

“He built an innovative company that helped supercharge our economy. FedEx changed the way we live and do business,” Bush said in the statement.

“My Yale fraternity brother loved America. He was a citizen, not a spectator.

“He served as a Marine in Vietnam and was rightly proud of his association with our military.

“I twice asked him to serve as Secretary of Defence, and he declined twice only because of his devotion to his family.

“Laura and I send our condolences to Fred’s beloved children and grandchildren and his wife, Diane.”