The pilot of an Aeronca 7AC stated that he intended to fly the airplane for one flight in the traffic pattern, followed by a landing and subsequent departure for a flight in the local area. He reported performing a preflight inspection and an engine run-up prior to departure, and that during the takeoff roll and initial climb, the airplane performed normally. The pilot began to initiate a slow left turn once the airplane had reached an altitude of 200 feet. During the turn the airplane rolled to the left, and the nose pitched down. The pilot reported attempting to correct the deviation with the input of right rudder. The airplane collided with terrain and an airport perimeter fence. During a subsequent telephone interview, the pilot stated that he applied too much left rudder input during the left turn, and the [left] wing "slipped away." A postaccident examination of the airplane and engine revealed no preimpact malfunctions, nor did the pilot report any.