Name That Bush

This is the big ugly bush in the backyard that I need to identify so that I can figure out how I'm suppose to prune it. Actually, I don't want to prune it, I want to cute it back to about 25% of its current size so that It won't look so awkward in the garden. I don't know what this is but I see them all over my neighborhood. It blooms in early spring with beautiful white flowers that make the entire think look like cotton. I think it has multiple stems but I'm afraid to look under there because there is lots of action goin on in the bush. Birds, rabbits, cicadas, you name it... If you know the name of this bush, please tell me. If you know how I can cut it back (way way back) without killing it or preventing it from blooming next spring - even better!