engine will not turn over

Was driving down the highway yesterday when the engine sort of lost power and stalled. Pulled over turned the key and it tried to fire up, stopped for a moment then tried again and nothing. I have lights but aside from that nothing. The car is a 69 gts 383 4sd which just came out from a 3 year restoration. I should mention the motor has ran for a total of about 1 hr. What could be the possibilities, thanks Bob.