Interstate TDR-1-- Part 1: Drones the Brainchild of Lt. Delmer S. Fahrney

From Wikipedia.

The Interstate TDR-1 was an early unmanned combat aerial vehicle referred to as an "assault drone" and developed by Interstate Aircraft  and Engineering Corporation  during WW II for use by the Navy

It was capable of being armed with bombs or torpedoes and 2000 were ordered, but only 200 built.  They saw some service in the Pacific Theater against the Japanese, but continuing developmental problems along with the success of more conventional weapons, led to the decision to cancel the building program in October 1944.

The idea to use drones was first put forth by Lt. Delmer S. Fahrney in 1936, but due to limitations in technology at the time, nothing came of it until the early 1940s with the development of the radar altimeter and television made the project more feasible.

Trials were made using converted manned aircraft and the first operational test of a drone against a naval target was conducted in April 1942.  That same month, following trials at Naval Aircraft factory TDN, Interstate Aircraft received a contract  from the Navy for two prototype and 100 production aircraft to a simplified and improved design to be designated TDR-1.

--GreGen