How did a gun hobbyist club morph into one of the most powerful political organizations in the U.S.? Here's everything you need to know:

When was the NRA founded?

In 1871, by two Civil War veterans in New York — one of them a former New York Times reporter. They, along with the National Rifle Association's first president, Union Gen. Ambrose Burnside, hoped to improve the dismal shooting abilities of the average Union soldier. (Yankee troops fired 1,000 rounds for every bullet that struck a Confederate soldier, according to an official study.) Their original mission focused on hunting, conservation, and marksmanship; there was no mention of protecting the Second Amendment right to bear arms. Indeed, for nearly a century, the NRA actively lobbied for gun control — ​co-authoring gun restrictions with the government right up until the 1970s. "Historically," says UCLA law professor Adam Winkler, "the leadership of the NRA was more open-minded about gun control than someone familiar with the modern NRA might imagine."

What restrictions did they endorse?

The NRA backed the nation's first federal gun laws after the Prohibition Era, when tommy gun–wielding gangsters warred in the streets of Chicago. The National Firearms Acts of 1934 and 1938 placed heavy taxes and regulations on machine guns, sawed-off shotguns, and silencers; prohibited felons from owning weapons; and required gun owners to register with the federal government. NRA leader Karl T. Frederick not only endorsed the legislation, he went so far as to state, "I have never believed in the general practice of carrying weapons. I think it should be sharply restricted and only under licenses."

How long did that position last?

Right through the 1960s, when assassinations and street violence rocked the nation. When it emerged that Lee Harvey Oswald had used a rifle purchased via an NRA mail-order advertisement to assassinate President John F. Kennedy in 1963, NRA Executive Vice President Franklin Orth backed the banning of mail-order sales. And when members of the Black Panther Party marched on the California Capitol carrying shotguns and rifles, the NRA supported state legislation prohibiting "open carry" in public places. "There's no reason why on the street today a citizen should be carrying loaded weapons," said then-Gov. Ronald Reagan. After gunmen assassinated Martin Luther King Jr. and Robert F. Kennedy, Congress passed the Gun Control Act of 1968. The law imposed various new restrictions, including on the shipping of guns across state lines.

When did things change?

By 1968, there were rumbles of rebellion against gun control within the NRA. Though the organization supported the Gun Control Act, it blocked attempts to include a national gun registry and a requirement for all gun carriers to hold a license. Then in 1971, federal agents shot and paralyzed longtime NRA member Kenyon Ballew during a gun raid at his home in Maryland. Anti-government sentiment surged within the ranks, and hard-liners became increasingly impatient with the leadership's "soft" stance. Things came to a head on the night of May 21, 1977 — known in NRA lore as the Revolt at Cincinnati — when gun-rights radicals stormed the group's annual meeting in Ohio and demanded changes to the governing structure. The old guard was ousted, and new Executive Vice President Harlon Carter, who had served time for shooting dead a Mexican teenager, spelled out the new approach: "No compromise. No gun legislation." The NRA would become an organization "so strong," said Carter, "that no politician in America mindful of his political career would want to challenge [our] goals."

How did it build its power?

The NRA began grading politicians from A to F on gun-control legislation. Those with the best report cards were given campaign money; the rest earned the wrath of the NRA's ballooning membership, which tripled following the Cincinnati revolt. Sen. Bob Dole (R-Kan.) complained of a "litmus test every five minutes." The leadership adopted a new motto — "The Right of the People to Bear Arms Shall Not Be Infringed" — and waded deeper into the culture wars, fueled by the spread of Waco-inspired conspiracy theories about gun-confiscating government forces in black helicopters. Each piece of gun legislation was framed as the first step toward total disarmament, driving members to the ballot box. By 2000, new NRA President Charlton Heston was challenging Democratic presidential candidate Al Gore to pry Heston's Colonial-era musket "from my cold, dead hands." Gore lost the election; a year later, Fortune named the NRA the most powerful lobbying group in Washington.

What about recent years?

Led by Executive Vice President Wayne LaPierre, the NRA continues to exert huge political influence. In 2013, when support for universal background checks rose to 91 percent after the Sandy Hook Elementary School shooting, the organization blocked congressional efforts to pass background-check amendments. The activism of its 4 million members is perhaps its strongest asset. Gun-rights supporters are four times as likely to have donated money and written a politician about the issue as gun-control advocates, according to one study. Those members are unmoved by stories about their early leaders' support for gun control. "Then was then," said one NRA supporter recently, on Guns & Ammo's online forum. "Now is now."

The corporations calling the shots

The NRA used to tout its independence from gun manufacturers — branding itself as the century-old voice of average-joe hunters and sport shooters. Today, though, the organization bolsters its funds with million-dollar donations from 22 different gun makers, including Smith & Wesson and Beretta USA. The NRA received up to $52.6 million in industry donations between 2005 and 2013, according to one report — and from some gun and ammo companies, it makes $1 from every purchase. The gun manufacturers' influence is clear: Today, the NRA's answer to every mass shooting is more firearms — even in schools and churches. "Today's NRA is a virtual subsidiary of the gun industry," said Josh Sugarmann, executive director of the Violence Policy Center, a gun-control organization. "While the NRA portrays itself as protecting the freedom of individual gun owners, it's actually working to protect the freedom of the gun industry to manufacture and sell virtually any weapon or accessory."