How safe is it to live in the United States?

Depends on where you want to live in the US. This is a very big country, but generally it is quite safe to live in the US compared to say Afghanistan, Pakistan or Iraq.

Anywhere between "bring your mase in your purse everywhere, everyday." to "no one in this town ever locks their doors."

Even in my home state of Wisconsin, there are extremes. In Milwaukee, it is vital to walk with someone else or at least have a way to defend yourself in the bad neighborhoods. In some small towns, the worst thing that ever happens is a tractor creates a traffic jam on the main road.

In general, smaller to medium sized towns are always going to be safer than big towns.

in comparison to where? I think it also depends on what part of the US you are referring to.... there are safe places and there are some not so safe places... I love America and am proud to live here!

Depends where you live but the worst place in the US is like the best place in Iraq,Lol its the safest country.Just dont move into like a gang related area and mostly youll be fine.

It depends on where you live. In general it is really safe.

That is an extremely subjective question? Where in the US?