US Customs @1000 Is. Bridge -- Need Advice

I just returned to the US on Sat. (7/13) a.m. vis the 1000 Is. Bridge. As I approached US customs, traffic was stopped even before the entrance to the duty free shop. It was only 7:30 a.m. at the time. It took one hour and ten minutes to get through customs. When it was finally my turn, the officer only asked two questions. All the while, there was no delay at all for those entering Canada. In any case, does anyone know if this delay was unusual or if it can be avoided by passing through the US customs in the very early morning hrs. (4:00 -- 6:00 a.m.)??? Although I certainly understand and appreciate the need for the extraordinary precautions, if arriving at customs earlier would avoid this lengthy wait then I would be more than willing to sacrifice some sleep and leave earlier.