IRS targeting | 2013 – Officials in the Obama administration's Internal Revenue Service came under fire after revelations that workers in its Cincinnati office targeted for extra scrutiny tea party and conservative groups applying for 501(c)(4) tax-exempt status.
Benghazi | 2012 – President Barack Obama and former Secretary of State Hillary Clinton came under intense scrutiny about the handling of the investigation of the attack on the U.S. Consulate in Benghazi, Libya, that led to the death of Ambassador Chris Stevens and three other embassy employees.
Iraq War | 2003 – When President George W. Bush addressed the nation aboard the USS Abraham Lincoln in May of 2003, standing in front of a "Mission Accomplished" banner, few expected that the U.S. involvement in the deadly Iraq War would last for another eight years.
CIA/Plame leak | 2003 – Former CIA covert agent Valerie Plame Wilson had her identity revealed by George W. Bush's Deputy Secretary of State Richard Armitage after her husband wrote a scathing op-ed in The New York Times.
Monica Lewinsky | 1998 – President Bill Clinton was ultimately impeached by Congress after he lied under oath about an affair he had with White House intern Monica Lewinsky.
Iran/Contra pardons | 1992 – President George H. W. Bush pardoned former Defense Secretary Caspar W. Weinberger and five other officials who served under Ronald Reagan for their involvement in trading arms for hostages in Iran.
Iran-Contra | 1986 – Senior officials working for President Ronald Reagan secretly arranged for the sale of military weapons to Iran with the hope that American hostages held there would be released and the proceeds could be used to fund the Contras fighting in a rebellion in Nicaragua -- a violation of the Boland Act that expressly prohibited U.S. funding of the rebels.
Iran hostage crisis | 1979 – For 444 days -- ending in what would be the final year of his presidency -- President Jimmy Carter sought to gain the release of 52 Americans held hostage at the U.S. Embassy in Tehran, Iran.
Watergate pardons | 1974 – In one of his first acts as president, Gerald Ford granted "a full, free and absolute pardon" to former President Richard Nixon for all crimes he may have committed while president, including his involvement in the Watergate scandal.
Watergate | 1974 – President Richard Nixon resigned his office after being implicated in a cover-up following a burglary at political offices in the Watergate building.
Agnew resigns | 1973 – Spiro T. Agnew, who served as vice president under President Richard Nixon, resigned his position after being indicted for bribery charges, becoming the first U.S. vice president in history to resign under criminal charges.
Pentagon Papers | 1971 – The Pentagon Papers, a top-secret document that detailed U.S. decisions leading up to the Vietnam War, were leaked to The New York Times by military analyst Daniel Ellsberg. The Nixon administration obtained an injunction to stop their publication.