It hasn't always been that way. Founded in 1871 to teach marksmanship to city-dwelling Union soldiers, the group was originally a nonpolitical and noncontroversial league of sportsmen and remained so for nearly a century. Everything changed, however, during the urban tumult of the 1960s, culminating in the assassinations of Martin Luther King Jr. and Robert Kennedy. The 1968 Gun Control Act imposed a licensing system for purchases, mandated serial numbers on weapons, banned certain gun imports and barred felons and illicit drug users from obtaining firearms. Gun-loving legislators like Representative John Dingell of Michigan worried that even harsher restrictions were imminent and clamored for the N.R.A. to wake up and enter the political arena. The lobbying arm, the Institute for Legislative Action, was formed in 1975. Two years later at a now-famous annual convention in Cincinnati, Dingell and other N.R.A. allies ousted the group's reigning executives, who saw the organization largely as a haven for gentlemen hunters, and replaced them with fire-breathing Second Amendment absolutists.