Sounds like cheezie brake pads on the front (low friction co efficient) and possibly frozen wheel cylinders in the rear. Have you looked the entire system over?
Also if the pads in the front are rusted into the mounting area and wont move(without a hammer) then they wont apply well either. Believe it or not that is a common issue, especially in the rust belt.
Service the fronts pads/mount area, making sure the pads slide freely, check the rear to be sure the wheel cylinders move when you step on the brake.
Fact is stranger than Fiction