I never know which I like more, the Harvards or the Pitts Specials. They definitely cannot be beaten when it comes to acrobatics.The real lineage of the Harvard began in 1937 with a USAAF competition to develop a basic trainer.
The requirements were for a type capable of basic instruction as well as simulating the controls and feel of an actual combat aircraft. It also had to be able to carry guns and bombs as necessary.
North American's new design was based on their NA-16, but was vastly improved.
It incorporated the Wasp engine, A Hamilton Standard variable pitch prop, a hydraulic system to power the flaps and the new inward-folding retractable landing gear.
Later a stressed skin fuselage, a new rudder and angular wingtips were added.
This prototype (called the NA-26) won the competition. It went into production as the BC-1. (BC for "basic trainer")
The Royal Air Force initially ordered several hundred of this variant, with British instruments and radios, in 1938. The Brits coined the name "HARVARD" for it. (by which name it would become known in all the commonwealth countries....except for
Information from: http://www.spitcrazy.com/harvardhist.htm