The original XF4F proposal was a biplane like the plane it was to replace,
the Grumman F3F. Because Brewster was proposing a monoplane, Grumman
changed their design.
The prototype first flew in 1937. Problems with
engine overheating delayed production until 1940 with deliveries to front-line
squadrons just in time to be available at the outbreak of WWII.
The Wildcat
held the line against Japanese juggernaut in the early battles in the Pacific
until replaced by (you guessed it) the Grumman F6F Hellcat late in 1943.
Note:
the landing gear design on the Wildcat had been pioneered by Grumman, in
fact was responsible for Grumman's pre-eminence in U.S. Navy fighter
aircraft in the late thirties. Grumman entered the aviation world in
1930 with a center float with retractable landing gear for U.S. Navy
floatplanes (the Model G-1).