Benefiting from early combat experience in World War II, the US Navy drew up its. specification for a new single-seat carrier-based attack aircraft. The Martin Model 210 design proposal gained a contract for two XBTM-1 prototypes, the first being flown initially on 26 August 1944. A cantilever low-wing monoplane with retractable tail-wheel landing gear, powered by a 2237kW Pratt & Whitney XR-4360-4 radial engine, the XBTM-1 was tested successfully and gained a contract for 750 BTM-1 series aircraft. By the time that the first of these was flown, on 16 December 1946, the designation had been changed to AM-1 and the name Mauler selected. World War 11 had also ended, and instead of the planned procurement only 149 AM-1s (excluding prototypes) had been completed when production ended in October 1949. Initial deliveries to an active unit went to Attack Squadron VA-17A on 1 March 1948, but these aircraft saw little first-line service, being transferred to US Navy Reserve squadrons when production ended. The total of 149 built included 17 AM-1Q aircraft completed as ECM (electronic counter-measures) aircraft.