1921: President Harding forms the Veterans Bureau, which soon becomes notorious for limited accomplishments and widespread corruption.
1924: Congress enacts bonus to compensate veterans for the higher pay that civilian defense factory workers received during World War I.
1932: Army veterans demanding an early payout of the bonus to help them weather the Depression march on Washington and set up "Hooverville" encampment. ... Repression of the "bonus army" on orders from Republican President Hoover helps Democrat Franklin D. Roosevelt win the presidency.
1945: Roosevelt and Congress create the GI Bill. Millions of veterans use its benefits to attend college and buy homes, vastly expanding the nation's middle class.
1953: Veterans returning from the three-year Korean conflict get a new, less generous GI Bill but are not welcomed as warmly as World War II vets.
1967: Vietnam Veterans Against the War is founded.
1970: Senate Subcommittee on the Environment holds hearings on Agent Orange, a chemical defoliant used during the Vietnam War. Soon after, Pentagon bans use of dioxin, the chemical used in the defoliant.
April 1971: Veterans at anti-war demonstration in Washington -- including future Sen. John Kerry, D-Mass. -- protest by tossing their medals onto the Capitol steps.
Nov. 13, 1982: Vietnam Veterans Memorial opens on the National Mall bearing the names of 58,249 dead or missing servicemen and women.
1984: Veterans claiming serious illness from dioxin sue the government.
1992: Veterans of the 1990-91 Persian Gulf War begin reporting ailments collectively dubbed "Gulf War syndrome" and attributed to possible chemical exposure.
1997: Researchers report in the Journal of the American Medical Association that "Gulf War syndrome" results from exposure to combinations of pesticide and nerve gas.
2003: Improvised explosive devices begin wreaking havoc on U.S. troops -- including multiple loss of limbs.
Dec. 22, 2005: Army Reserve Spc. Joshua Omvig, 22, commits suicide after an 11-month tour in Iraq; his parents say he had post-traumatic stress disorder.
2006: Government Accountability Office says military efforts to treat symptoms of post-traumatic stress fall short. Joshua Omvig Veterans Suicide Prevention Act introduced in House in July, charges Veterans Affairs with setting up a program to screen and monitor for suicide risk.
2007: Amid reports of shocking conditions for outpatients at Walter Reed Army Medical Center, Army secretary and two top medical officers are forced out. ... Presidential panel urges simplifying disability-rating process and other changes in veterans-care system. ... Congress takes up legislation on veterans' benefits.