I got the engine rebuilt and put back in and all my electrical hooked up on Saturday but when I turned the key I had nothing. There is no power at all the interior lights don't even light up. I checked all my connections and everything looks good. I even have a new battery. What could I be missing?

 

Try checking your ground

 

There is an engine to firewall ground near the heater blower required as well.
Jim

 

When you check the grounds make sure there's no paint between the cable/strap and frame/block, and, I apologize in advance for stating the obvious, make sure everything is tight.

 

Check for voltage at the fuse box. No votage? Then the trouble lies between the fuse box and the solenoid. Got voltage? Then go back and check every wire between the fuse box and ignition switch until you get voltage at the ignition switch.

 

In addition to all of the other fine answers provided, check that the the firewall connector outboard of the brake booster/master cylinder is not loose.

 

Yeah, if there is no juice to the fuse box, that is about the first thing that should be checked.