Factbox: Decades of calls for gun control in U.S., but little action

(Reuters) - Monday's shooting in Boulder, Colorado, spurred a new round of calls for federal action on gun control, with President Joe Biden urging Congress to swiftly pass legislation. White House spokeswoman Jen Psaki said Biden was also "considering a range" of executive actions designed to stop gun violence.

The calls, following a mass shooting in a grocery story that left 10 people dead, are just the latest in a decades-long quest by many - largely Democrats - to enact measures to make it more difficult to buy firearms and restrict the type of weapons for sale.

But impassioned calls for action after mass shootings that have killed first-graders in Connecticut, both high-schoolers and nightclub goers in separate attacks in Florida, and music fans in Las Vegas have borne little legislative fruit. And some successful measures have later been watered down or overturned.

What follows is a brief history of efforts in recent decades.

The 1960s

The Gun Control Act of 1968 established minimum ages for firearms purchases, a requirement that all firearms carry a serial number and an expanded category of prohibited persons.

The 1980s

In 1986, the 1968 Gun Control Act was amended, easing restrictions on firearms sellers, allowing the sale by licensed dealers away from the location shown on a dealer's license if at a gun show in the same state.

The 1990s

The Brady Handgun Violence Prevention Act of 1993 imposed a five-day waiting period on handgun purchases to allow for background checks. The waiting period was later replaced by an instant check system, which can be extended by three days. People with a federal firearms license or a state-issued permit to possess or acquire a firearm aren't subject to a waiting period. With more states having enacted "shall issue" concealed carry permit laws, more people are exempt.

In 1998 the law became applicable to shotguns and rifles.

In 1994 the Federal Assault Weapons Ban was enacted, prohibiting the manufacture, transfer and possession of semi-automatic assault weapons and the transfer and possession of large-capacity ammunition feeding devices. Only weapons and ammunition-feeding devices manufactured after the enactment of the law were banned. The law had a sunset provision saying it would expire in 10 years. Congress allowed it to expire in September 2004.

The 2000s

In 2013, a bipartisan gun control bill, proposed after the December 2012 Newtown, Connecticut, school shooting that killed 20 first-graders and others, failed in the Senate after falling short of the 60 votes needed for passage.

In 2016, after the December 2015 mass shooting in San Bernardino, California, President Barack Obama signed executive orders designed to strengthen background checks.

In 2017, after the Las Vegas shooting - the deadliest mass shooting in America's history - Democratic U.S. lawmakers called for stronger checks on gun sales.

In February 2017, President Donald Trump signed a measure rolling back an Obama order that made it harder for the mentally ill to buy guns.

In December 2018, the Trump administration banned the type of high-powered gun attachments used in the Las Vegas massacre. The attachments enable a semi-automatic weapon to fire hundreds of rounds per minute.

In February 2019, the U.S. House of Representatives passed a bill to expand background checks. It died in the Senate.

In August 2019, survivors of the Parkland school shooting in Florida released a gun control plan to ban assault-style weapons.

On March 11, 2021, the House of Representatives passed two bills to broaden background checks. They face an uphill battle in the Senate, where some Republican support would be needed to reach the 60-vote threshold for passage.