Till the 1920 Census, most Americans lived in Rural areas. The 1920 Census is the first Census where more people lived in Urban Areas then Rural areas. This will screw any figures if you just want to compare towns.
Furthermore, prior to the 1960s every US city had lower then average Murder rates. The reason for this was the extremely high murder rate in the Rural South. That high murder rate was first noted in Colonial times (and believed tied in with Slavery i.e. the easy killing of another Human Being just because he was at the wrong place at the wrong time, characteristic of the Rural South during the time Slavery was the law. Whites were required to do a "patrol" once a month and during that "Patrol" could kill any black man with impunity just be saying the black was going about setting up a slave revolt).
The South Rural High Murder Rate survives to this day. The High Murder rates of the inner cities of the 1960s are believe to be tied in with the movement of former rural southern blacks to such cities (and bring with them the rural south tradition of high murder rates) and the subsequent drop in inner city murder rares in such cities the reflection of the children and grandchildren (and great grandchildren) of sch former rural southern blacks slowly adopting the Northern Norm of much lower rates of Murder (True even in the Rural North).
Much of the Gun culture of the old west came from the Rural South. You did NOT see it in areas where Northerns (or Europeans) moved to, but you did see it where Southern Whites moved to (And the quick decline in such Murder rates may be tied in with the Rural Southerns quickly being replaced by Northerns as the west settle down).
High Southern Rural Crime rates:
http://www.nytimes.com/1998/07/26/weekinreview/ideas-trends-southern-curse-why-america-s-murder-rate-is-so-high.html?pagewanted=1http://www.ncrel.org/sdrs/areas/issues/envrnmnt/drugfree/v1donner.htmhttp://books.google.com/books?id=K90Vsdr2YZsC&pg=PA81&lpg=PA81&dq=High+South+Rural+Murder+Rate&source=bl&ots=HMVk1cWWGU&sig=IZQAYlkDA3yoozQ4qLbNnAUjY9U&hl=en&ei=YYqQS4GzIJ2H8QbWh6yoBQ&sa=X&oi=book_result&ct=result&resnum=10&ved=0CD4Q6AEwCQ#v=onepage&q=High%20South%20Rural%20Murder%20Rate&f=falseSome other comments on the North-South difference:
http://www.democraticunderground.com/articles/04/11/23_war.htmlhttp://www.psychologytoday.com/blog/the-human-beast/200904/is-southern-violence-due-culture-honorhttp://www.ag.auburn.edu/auxiliary/srsa/pages/Articles/SRS%202008%2023%202%20157-170.pdfhttp://heinonline.org/HOL/LandingPage?collection=journals&handle=hein.journals/jquart6&div=47&id=&page=http://www.epjournal.net/filestore/ep03381391.pdfA 1996 experiment to test the tendency for violence among Southern White Males compared to Northern White Males:
http://chiron.valdosta.edu/mawhatley/9710/honor.htmAnother study on the same subject:
http://etd.lsu.edu/docs/available/etd-07022006-123237/unrestricted/Hayes_dis.pdfAlcohol and Suicide:
http://www.physorg.com/news172513898.html