Executive orders aren’t mentioned once in the U.S. Constitution, but presidents starting with George Washington have used executive orders and proclamations in order to bypass Congress and quickly exercise the independent power of their office.

Franklin D. Roosevelt is the undisputed king of the executive order, issuing 3,721 of these signed and published directives during his 12 years in office. (Most presidents issued a few hundred or less.) In recent decades, newly inaugurated presidents sign a flurry of executive orders to reverse the policies of their predecessors; but while they have the force of law and must be carried out, few have a lasting impact. Here are at least 10 executive orders that altered the course of history and changed the fabric of American life.

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1. The Emancipation Proclamation (1863)

Abraham Lincoln and the Emancipation Proclamation
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President Abraham Lincoln signing the Emancipation Proclamation on January 1, 1863, in Washington, D.C.

When Abraham Lincoln issued his historic Emancipation Proclamation on January 1, 1863, the Civil War officially became a war to end the shameful practice of slavery in the United States. It’s important to note, however, that the Emancipation Proclamation itself didn’t end slavery. Lincoln specified that enslaved people in the Confederate states “are, and henceforward shall be free,” but made no such provision for those in border states. He also welcomed formerly enslaved people into the Union Army and Navy, in which some 200,000 Black soldiers ultimately enlisted.

While the Emancipation Proclamation didn’t abolish slavery, it signaled that the freedom of enslaved people in the South depended on a Union victory, and it imbued the bloody conflict with a clear moral imperative. The 13th Amendment, signed and ratified in 1865, officially abolished slavery in America.

2. Funding for the Manhattan Project (1941)

"Little Boy" bomb, Hiroshima, World War II
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A group of men preparing 'Little Boy,' code name for the atomic bomb that was dropped on Hiroshima in 1945

The United States didn’t enter World War II until the Japanese bombed Pearl Harbor on December 7, 1941, but months earlier President Franklin D. Roosevelt issued Executive Order 8807 to create a government agency overseeing scientific research into defense technology. Funding from the newly created Office of Scientific Research and Development paid for the massive, top-secret nuclear weapon program known as the Manhattan Project.

As early as 1939, FDR was alerted that German scientists were working on a new type of bomb with unrivaled destructive power. American and British physicists set to work on achieving nuclear fission with uranium, and a few months after issuing Executive Order 8807, FDR secretly approved the creation of the Manhattan Project. More than 130,000 people contributed to the effort, at a cost of $2 billion ($29 billion in 2022).

3. Mass Incarceration of Japanese Americans (1942)

It’s one of the darkest chapters of American history. On February 19, 1942, roughly two months after the Japanese attack on Pearl Harbor, President Franklin D. Roosevelt issued Executive Order 9066, authorizing the U.S. Secretary of War to “prescribe military areas…from which any or all persons may be excluded.”

As a result, more than 120,000 Japanese Americans, many of them U.S. citizens by birth, were forcibly removed from their homes and confined in “relocation centers” that could more accurately be called concentration camps.

The government created 10 such “relocation centers,” where they incarcerated Japanese Americans (men, women and children) in remote locations under harsh conditions. The last of these camps closed in 1946.

4. Desegregation of the U.S. Military (1948)

More than a million African American men and women served their country in World War II, but they did so in racially segregated units. The U.S. military followed the segregation model of the Jim Crow-era South, built upon the lie that Black servicemen were inherently less capable than whites. Despite these racist policies, Black units like the 332nd Fighter Group (Tuskegee Airmen) and the 761st Tank Battalion (Black Panthers) fought with “conspicuous courage” and valor.

In belated recognition of that service and sacrifice, President Harry S. Truman issued Executive Order 9981 in 1948 to maintain “equality of treatment and opportunity for all those who serve in our country's defense” for all American servicemen and women “without regard to race, color, religion or national origin.” Desegregating the U.S. military set a huge precedent that significantly advanced the cause of civil rights.

READ MORE: Why Truman Ended Segregation in the Military in 1948

5. LGBTQ Workers Barred from Government Jobs (1953)

American gay rights activist Frank Kameny (1925 – 2011), second in line, protesting with others outside the White House on Armed Forces Day, Washington, D.C., May 15 1965. The demonstrators were protesting "the issuance of less-than-fully honorable discharges to homosexuals in the Armed Forces."
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Gay rights picketers protesting outside of the White House, 1965

After World War II, anti-communist crusaders like Senator Joseph McCarthy strove to purge the U.S. government of suspected communists during a period known as the “Red Scare.” Many of those same politicians falsely claimed that gay and lesbian government workers were also a threat. Since homosexuality was still a crime in the 1950s, communists could allegedly blackmail LGBTQ workers to share government secrets. Others insisted homosexuals were simply “morally unfit” for government service.

In 1953, President Dwight D. Eisenhower cemented decades of anti-LGBTQ discrimination with Executive Order 10450, which identified “sexual perversion”—a code word for homosexuality—as a valid reason for rejecting an application or firing a federal government worker. This discriminatory ban wasn’t fully lifted until 2017 with President Barack Obama’s Executive Order 13764. The homophobic targeting of LGBTQ workers as “anti-American” is now known as the “Lavender Scare.”

6. National Guard Deployed to Desegregate Public Schools (1957)

Why Eisenhower Called in the 101st Airborne After Brown v. Board, Little Rock Nine
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Minnijean Brown, 15, arriving with 8 others of the 'Little Rock Nine' outside Central High School, as members of the 101st Div. of the Airborne Command stand ready to protect them, under order of President Eisenhower.

In 1957, three years after the U.S. Supreme Court’s historic ruling in Brown v. Board of Education, the segregationist governor of Arkansas refused to allow the desegregation of the all-white Central High School in Little Rock. When nine Black students tried to enroll there, they were stopped by members of the Arkansas National Guard while an angry crowd jeered and spat on them.

The saga of the “Little Rock Nine” made national news, and President Dwight D. Eisenhower, while not passionate about Civil Rights, was a military man who believed in law and order. Eisenhower issued Executive Order 10730, authorizing the deployment of the National Guard and active-duty military to enforce both federal and state court orders for the desegregation of Arkansas schools. These armed officers escorted the brave members of the Little Rock Nine to class.

READ MORE: Why Eisenhower Sent the 101st Airborne to Little Rock After Brown v. Board

7. Creation of the Peace Corps (1961)

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President John F. Kennedy signing the bill creating the Peace Corps

In his inaugural address on January 20, 1961, President John F. Kennedy issued his famous patriotic challenge to all Americans: “Ask not what your country can do for you, ask what you can do for your country.” During his campaign, JFK proposed a similar challenge to his young supporters, to promote the cause of freedom by living and serving people in developing countries.

Less than two months into his presidency, JFK signed Executive Order 10924, formerly creating the Peace Corps as an agency within the U.S. State Department. Thousands of young Americans applied, and by the end of 1961, 750 inaugural Peace Corps volunteers had served in 13 countries. Since 1961, more than 240,000 Peace Corps volunteers have served in 142 countries.

8. Affirmative Action in Government Contracting (1965)

The fight for equal rights in government contracting began in 1941 when Black union leader A. Philip Randolph protested the exclusion of African Americans from working in segregated war production factories. FDR responded with an executive order barring racial discrimination in the federal government and defense industry, but the racist hiring practices persisted.

JFK made progress with a 1961 executive order requiring government contractors to “take affirmative action to ensure that applicants are employed, and that employees are treated during employment, without regard to their race, creed, color or national origin.” But it was President Lyndon B. Johnson who, as part of his “Great Society” initiative, gave teeth to affirmative action in Executive Order 11246 by giving the Secretary of Labor the power to enforce anti-discrimination policy in government contracting.

The Department of Labor estimates that 20 percent of the U.S. workforce is now protected by LBJ’s Executive Order 11246.

READ MORE: Did World War II Launch the Civil Rights Movement?

9. Pardon of Richard Nixon (1974)

How American Presidents Ended Up With the ‘Kingly’ Power to Pardon
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<em>September 8, 1974:&nbsp;</em>President Gerald Ford informs the American people of his decision to pardon Richard Nixon of any crimes he may have committed during the Watergate scandal.

On August 9, Richard Nixon boarded a helicopter on the White House lawn and became the first American president to resign from office. With evidence mounting against him in the Watergate scandal, Nixon chose to resign rather than be impeached and potentially removed from office by Congress. Gerald Ford, who had only served eight months as Nixon’s vice president, was hastily sworn in as president.

Only a month into his unexpected presidency, Ford made the controversial decision to issue a “full, free and absolute” pardon to Nixon, freeing the disgraced former president from facing a criminal trial related to Watergate. While critics roared, Ford defended his action, known as Proclamation 4311.

“The prospects of such trial will cause prolonged and divisive debate over the propriety of exposing to further punishment and degradation a man who has already paid the unprecedented penalty of relinquishing the highest elective office of the United States,” said Ford in the proclamation.

Decades later, even fierce critics like the Watergate journalist Bob Woodward called the pardon “an act of courage” that helped the nation heal, while almost certainly costing Ford his political career.

10. Creation of the Department of Homeland Security (2001)

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President George W. Bush speaking about homeland security, as Director of Homeland Security Tom Ridge (L) listens.&nbsp;

A month after the shocking terrorist attacks of September 11, 2001, President George W. Bush signed Executive Order 13228 creating the Office of Homeland Security within the White House. The Office and its first director, Tom Ridge, were tasked with developing and coordinating a national strategy for combating a new type of security threat.

It became clear that responsibility for the nation’s homeland security was spread across more than 100 different overlapping departments and agencies, often with poor cross-communication. So, in 2002, Bush proposed the creation of a unified Department of Homeland Security that combined 22 existing federal agencies. In Bush’s words, it was “the most significant transformation of the U.S. government in over a half-century.”