It looks like something a kid would dream up, but they really built them. They were too late to participate in WW2, but they proved to be quite effective in the Korean War.
"On 27 February 1947, P-82B 44-65168, named Betty Jo and flown by Colonel Robert E. Thacker, made history when it flew nonstop from Hawaii to New York without refueling, a distance of 5,051 mi (8,129 km) in 14 hr 32 min. It averaged 347.5 miles per hour (559.2 km/h).P.S. Note that the record is for "a propeller-driven fighter", not a propeller-driven airplane.
To this day, it remains the longest nonstop flight ever made by a propeller-driven fighter, and the fastest such a distance has ever been covered in a piston-engined aircraft"