It is estimated that in the late 1600s the U.S. homicide rate was over 30 per 100,000. In the 1800s it was in the high to mid teens. Today it is under five per 100,000. According to FBI statistics, the murder rate in the U.S. fell from 9.3 per 100,000 in 1992 to 4.7 per 100,000 in 2011, a reduction of almost 50%. Overall violent crime in that same time period fell from 757.7 per 100,000 to 386.3 per 100,000 [ref]. This in spite of gun ownership in the United States trending upwards over the same time period [ref].
Mass shootings in the United States are also trending downward. Criminologist James Allen Fox of Northeastern University in Boston has been studying mass shootings since the 1980s. His research shows that there is no pattern or increase [ref].
Criminologist Grant Duwe, author of Mass Murder in the United States: A History, found that mass killings in the United States peaked in 1929. His data shows an upward trend (but still below the 1929 peak) between 1960 and 2000, followed by a decline in the 2000s [ref].
Over the long term European homicide rates have also declined significantly, dropping from an estimated 40 per 100,000 in the 15th century, to under 2 per 100,000 in the 20th century [ref]. However, recent trends, as we have already discussed elsewhere on Truth is Reason, show an increase in violent crimes and homicide — in spite of ever-tightening gun control and fewer legally-owned firearms [ref, ref].