Given the very dark-looking legs, I'd figure it's not the only US problem biter that's brown (Recluse). All the other hundreds of brown spiders are quite harmless, so my money is on that category for yours. For future reference, a photo is very helpful, but in order for a photo to be useful, we have to be able to see more than a mushed-up corpse. If it's dead, just stretch out the legs and take the shot from overhead so we can see the body and leg patterns, as well as the body shape.