A glance at changing public access and security at the White House through history:
1790s _ People wander with impunity through the construction site while the Executive Mansion is being built. Eventually, a pass is required to get inside the site.
1801-1809 _ President Thomas Jefferson opens doors of the mansion each day so visitors can freely browse the staterooms. One early rule is that the building is closed to the public only during early morning hours and when the president is asleep or out of town.
1800-1900s _ Through the first quarter of 20th century, Jefferson's successors and their wives continue to greet visitors briefly in the East Room each day at lunch.
1814 _ President James Madison stations troops on White House grounds when hearing British forces are marching to Washington. They and the president flee before the British set fire to the mansion.
1829 _ Andrew Jackson's inaugural reception is overrun with raucous, drunken revelers, forcing the president to escape.
1840s _ An enraged mob burns President John Tyler in effigy outside the White House gates and, in a separate incident, an intoxicated painter throws rocks at him while he walks around White House south grounds.
1860s _ Military helps protect mansion during Civil War. Soldiers camp inside White House until Washington is fortified.
1898 _ Start of Spanish-American War leads to the first formal use of the Secret Service to protect the president.
1930 _ A well-dressed man walks through the White House front door. Police allow him to pass, assuming he is a Secret Service agent. The curious sightseer enters the dining room and interrupts President Herbert Hoover's dinner before an agent stops him.
1940s _ Free public access to White House grounds during daylight hours ends. Security measures will never be as relaxed as they were before World War II.
1974 _ An Army private steals a helicopter from Fort Meade, Md., and lands twice on White House grounds. The second time, he is met by a barrage of gunfire and is captured.
1974 _ A man claiming to be the Messiah crashes his car through the Northwest gate and drives up to the North Portico. Attached to his body are flares he says are explosives. He surrenders after four hours of negotiation.
1975 _ A man roams the White House grounds for about 90 minutes and approaches President Gerald Ford's daughter while she is unloading camera equipment from her car.
1980s _ Following terrorist attacks on the Marine barracks and U.S. Embassy in Beirut, concrete Jersey barriers are installed at the complex's perimeter.
1985 _ On the day President Ronald Reagan is sworn in for his second term, a man enters the White House with the Marine Band and wanders around for 15 minutes before he is discovered.
1991 _ An unarmed Swedish citizen enters the White House grounds and is not arrested until after he reaches a guard post outside the West Wing.
1993 _ After his inauguration, President Bill Clinton invites some 2,000 citizens selected by lottery to a receiving line in the Diplomatic Reception room.
1994 _ After smoking crack cocaine and drinking, Frank Eugene Corder finds the keys of an airplane and takes off, eventually heading toward the White House. His plane crashes on the lawn near the White House at top speed, hitting the southwest corner of the building and causing minimal damage. His death is ruled a suicide. Clinton and family are not at White House at the time.
1994 _ Francisco Martin Duran, on Pennsylvania Avenue, fires at least 29 rounds from a semiautomatic rifle toward the White House. Eleven rounds strike the White House facade. Duran is tackled by a passing tourist, and two other citizens run over to help subdue the shooter. Nobody is injured.
1995 _ Pennsylvania Avenue outside the White House is closed to traffic. That section of road remains a heavily guarded area open to pedestrians.
2001 _ Public tours of the White House are suspended after the terrorist attacks. They don't fully resume until two years later.
2008 _ Secret Service screens more than 1.2 million visitors at the White House complex.
2009 _ Tareq and Michaele Salahi get into the White House without invitations on the night of President Barack Obama's first state dinner.
Source: Public Report of the White House Security Review.