Your modern studies textbook is part of what the government or the authors want you to think -- remember that.
Search around for about 10 seconds and you'll find varying statistics, ways to analyze them, ways to critique them, and lengthy discussions as to what they mean -- on this very topic and on this very board. Statistics regarding total death can be found contrasted with statistics regarding comparative death (to other countries). But also, you will find studies that show crime decreases in the US when the citizens have guns, and statistics that the number of accidental deaths are far outweighed by the number of crimes people have stopped with their guns. There are about a bazillion ways to look at the issue.
So, go searching on the first 2-3 pages of this CE forum and see what you can find.