Here's a selected list of White House intrusions and security breaches.
Facts: The White House grounds include 18 acres of land. That and the adjacent 52-acre Ellipse to the south belong to President's Park, a national park.
The Secret Service is in charge of White House security.
According to the White House Historical Society, Thomas Jefferson was the first to put a fence around the White House. Over the years, the fence has been updated and fortified, with the wrought-iron fences of the 19th century replaced in the 1930s by a steel fence with tall bronze spears atop it. The current fence is about seven feet tall. There are plans to install a taller one in 2018.
Security became especially tighter during World War II. After a truck-bomb attack on the US Marine barracks in Lebanon in 1983, low concrete walls were put up around the White House. Bollards - sturdy, vertical posts that can stop vehicles - were added a few years later.
"Security incidents occur frequently," according to a 2015 House of Representatives report. Data from the Secret Service included in the report show that there were 104 security breaches or attempted breaches between April 2005 and April 15, 2015.
Timeline: April 13, 1912 - On his second attempt to enter the White House to see President William Howard Taft, Michael Winter makes it several feet inside the front door before being noticed.
September 26, 1963 - Doyle Allen Hicks rams his pickup truck through the gates and drives up to within 25 feet of the North Portico main entrance. When stopped, he tells guards that he must see the president, because communists are taking over his state, North Carolina.
February 17, 1974 - Robert K. Preston, an Army private, steals a helicopter from Fort Meade, Maryland. He hovers over the Washington Monument and White House grounds before leading two state police helicopters on an aerial chase around Maryland and Washington, DC. After more than an hour, Preston heads back to the White House, according to a state police officer. Officers shoot at the helicopter, forcing Preston to land. He reportedly was upset about flunking out of flight school.
February 22, 1974 - Samuel Joseph Byck tries to hijack a Delta passenger jet at Baltimore-Washington International Airport, with the plan to crash it into the White House. He forces his way on to the plane, killing an airport policeman and the copilot. Byck is killed by police before takeoff.
December 25, 1974 - Marshall Fields crashes his automobile through the Northwest Gate and drives it close to the North Portico. He threatens to blow himself up with explosives he has strapped to his body, which later turn out to be flares. After four hours of negotiation, Fields surrenders to officials.
November 26, 1975 - Gerald Gainous Jr. makes his way over the fence, hides for two hours on the grounds undetected and is able to get within five feet of Susan Ford, President Gerald Ford's daughter. Gainous jumps the fence three more times within the next year.
July 25, 1976 - Chester Plummer Jr. climbs over the White House fence carrying a metal pipe and starts running toward the White House. A guard chases him, yelling at him to stop. When he doesn't, the guard shoots and kills him. Plummer's motive is not discovered.
October 1978 - A barefoot man wearing a karate uniform and carrying a Bible with a knife hidden inside, scales the White House fence. He slashes two officers before White House guards are able to subdue him. The suspect, Anthony Henry, reportedly wanted to convince President Jimmy Carter to remove the phrase "In God We Trust" from US currency.
January 20, 1985 - Robert Latta, a meter-reader from Denver, follows the Marine Band into the White House before President Ronald Reagan's second inauguration ceremony. Latta wanders around the mansion for about 15 minutes before being arrested in the dining room.
September 12, 1994 - A man flying a stolen Cessna plane enters the prohibited airspace around the White House and crashes on the lawn just south of the Executive Mansion. The pilot, identified as Frank Eugene Corder, dies in the crash.
October 29, 1994 - Francisco Martin Duran, armed with a semiautomatic rifle, fires at least 29 rounds at the White House from the sidewalk on Pennsylvania Avenue. Duran is later convicted of attempting to kill President Bill Clinton.
May 23, 1995 - Leland W. Modjeski is shot by the Secret Service after climbing over a security fence and running toward the White House with a handgun that was later determined to be unloaded.
February 7, 2001 - Robert Pickett, an accountant who was fired from the IRS in the 1980s, fires shots outside the White House. Secret Service agents shoot him in the leg after a standoff lasting more than 10 minutes at the White House fence. President George W. Bush was not endangered, White House officials say later.
January 18, 2005 - Lowell Timmers, of Cedar Springs, Michigan, threatens to blow up his van in front on the White House, two days before President Bush's second inauguration, saying he has an explosive substance in the vehicle. The FBI, Secret Service and other authorities evacuate nearby buildings and shut down several blocks. Four hours pass before Timmers, who had demanded that his son-in-law be released from jail, surrenders.
April 9, 2006 - Brian Lee Patterson from New Mexico jumps the White House fence and makes it well inside the grounds before being stopped. It is the fourth time he has jumped the fence.
November 24, 2009 - A publicity-seeking Virginia couple, Michaele and Tareq Salahi, sneak into a White House dinner. The uninvited guests finesse their way through a security checkpoint staffed by uniformed Secret Service officers, according to congressional testimony by the agency's director Mark Sullivan. Sullivan apologizes for the breach, saying agents violated protocol by allowing the Salahis to enter without verifying that they were on the guest list.
November 11, 2011 - A gunman fires an assault rifle at the White House, hitting the residential wing of the building at least seven times. Secret Service supervisors fail to recognize the danger, dismissing the gunfire as a gang-related shootout rather than an attack on the White House, according to the Washington Post. Four days later, a housekeeper and a White House usher spot bullet holes in the residence. Five days after the shooting, the gunman, Oscar Ramiro Ortega-Hernandez is arrested at a Pennsylvania hotel. In 2014, Ortega-Hernandez is sentenced to 25 years in federal prison.
October 3, 2013 - An unarmed woman is shot and killed by a Secret Service agent and a Capitol police officer after she drives toward a security checkpoint near the White House, hits a barricade and speeds away. The woman is a 34-year-old mother battling postpartum depression, according to her sister. Her one-year-old daughter, seated in the back of the car during the chase, is unharmed.
September 11, 2014 - A man wearing Pokemon gear, and carrying a plush doll of the character Pikachu makes it over the White House fence and onto the north lawn, where he is apprehended. He is later identified as Jeffrey Grossman.
September 19, 2014 - After jumping the White House fence, 42-year-old Omar Gonzalez, of Copperas Cove, Texas, gets through the North Portico doors with a three-and-a-half-inch folding knife in his pants pocket, according to the Secret Service. In early accounts of the incident, the Secret Service claims the intruder didn't get past the portico doors. Days later, the Washington Post reveals the man had actually made his way past the front entrance, through the main hall and into the East Room, where he was apprehended.
October 22, 2014 - Dominic Adesanya, 23, of Bel Air, Maryland, jumps the White House fence and barely makes it onto the lawn before he is subdued as he fights off two police dogs, according to the Secret Service. Adesanya, who suffers from mental health problems, had been arrested in a previous White House breach, his father later says.
January 26, 2015 - The Secret Service locks down the White House shortly after 3 am after an officer spots a drone flying above the White House grounds before crashing on the southeast side of the complex. An employee of the National Geospatial-Intelligence Agency, a government entity with mapping and national security duties, later calls the Secret Service and admits that he was operating the drone for fun.
April 19, 2015 - Jerome R. Hunt, of Hayward, California, climbs the fence on the south side of the White House complex while carrying a suspicious package, later deemed harmless, and is cornered by security dogs.
November 26, 2015 - The Secret Service stops a man draped in an American flag after he jumps a White House fence during a Thanksgiving celebration at the executive mansion.
April 1, 2016 - A man tosses a backpack over the north fence and then jumps over, himself, when he is immediately arrested. His name is not released to the public.
March 10, 2017 - A man carrying a backpack with mace and a letter for President Donald Trump makes it onto the grounds and roams for more than 15 minutes before he is discovered and arrested by a Secret Service officer near the south entrance. The suspect, identified in court records as Jonathan T. Tran, 26, of California, tells the agency's officers that he was there to see the president.
March 21, 2017 - Marci Anderson Wahl of Everett, Washington, jumps a fence on the south side but gets stuck. Officers find her hanging by her shoelaces, which were "caught on top of the fence," according to a police report. Wahl is arrested two more times within the next week, near the Treasury Building and in Lafayette Park.