Cunningham reluctantly closed the West Palm Beach production facility in 1955 after the IRS changed the operation's tax classification from business to hobby, rendering it financially unviable. At the same time, Jaguar's VP in America and Team Cunningham driver Gordon Benett was orchestrating a courtship between Briggs and Jaguar's head, Sir William Lyons. Sir William had let it be known during a visit by Benett to Coventry that he would offer to Briggs three D-Type Jaguars if he would halt his own production of race cars. Bennett subsequently arranged two meetings between the two men, first at Le Mans and then at Watkins Glen, after which Sir William appointed Briggs as Jaguar's distributor in the Northeastern U.S.

The team returned from the disastrous 1955 Le Mans 24 Hours to begin campaigning the first of the Cunningham D-Types, with Sherwood Johnston at the wheel. They began winning immediately, even without benefit of the latest engines from Coventry. Johnston, who had started the 1955 season driving a Ferrari, finished the year as champion of the SCCA's hot new C/Sports Racing class after a number of exciting clashes with young Californian Phil Hill and his Ferrari Monza.

By this time it was no surprise to see the Cunningham caravan pull into a venue and set up an impressive camp, but it must have been a sight when, on May 20, 1956, the team showed up at Maryland's Cumberland circuit with an assortment of vehicles that included three pristine white-and-blue D-Type Jaguars for drivers John Fitch, Gordon Benett and Sherwood Johnston. A fourth D-Type, to be driven by New Jersey amateur Walt Hansgen, was entered by Boston Jaguar dealer Hanson McFee.

At the start of the C/Sports race, Hansgen jack-rabbited away and left the field behind for the duration. John Fitch managed to finish third, while Benett spun out of the running and Johnston failed to complete the race. Surveying the day's disappointing results, Cunningham and Momo had spotted a nugget, and two weeks later they hired Walt Hansgen. It was the beginning of one of racing's great partnerships; Briggs Cunningham, Alfred Momo and Walt Hansgen would dominate road racing on the East Coast for the next seven years.