In May 1864, Arlington National Cemetery conducted its first military burials. Since then, it has become the final resting place for approximately 400,000 people who served the U.S. honorably. This Memorial Day weekend, here's a look at 21 notable people you probably didn't know are buried there.

Lee Marvin (1924-87)

Marvin is best known for his Hollywood acting in the mid-60s. However, he also was a Purple Heart recipient who fought in World War II.

William Howard Taft (1857-1930)

Taft is the only person to have served as chief justice of the Supreme Court and president of the United States. Under President Herbert Hoover's direction, he was the first president to be buried at Arlington. Taft popularized the traditions of the seventh inning stretch and the president throwing the season opening pitch at Major League Baseball games.

Robert F. Kennedy (1925-68)

Kennedy was a World War II veteran, taking time off from Harvard to serve in the Navy. A former U.S. attorney general, he is buried adjacent to his brother with a simple wooden cross and a small gray foot marker.

John F. Kennedy (1917-63)

(Photo: John F. Kennedy Presidential Library and Museum)

John, like his brother, also served in World War II. President Kennedy was buried in Arlington after his assassination, and an eternal flame marks his gravesite.

Jacqueline Kennedy Onassis (1929-94)

The former first lady is laid to rest next to her husband.

Anita Newcomb McGee (1864-1940)

(Photo: U.S. National Library of Medicine)

McGee was the first female surgeon in the U.S. Army and also trained nurses for the Japanese Red Cross.

Grace Hopper (1906-92)

Admiral Grace Hopper during her retirement ceremony aboard the USS Constitution.

Rear Adm. Grace Hopper was one of the leading programmers in the Navy. In addition, she was one of the first computer programmers of the Harvard Mark I computer and coined the term 'bug' to describe a problem in a computer program.

Mary Lee Fitzhugh Custis (1788-1853)

Custis was the spouse of George Washington Parke Custis, who originally built the Arlington estate.

Mary Randolph (1762-1828)

A cousin of Thomas Jefferson, Randolph was the first person to be buried at the would-be Arlington National Cemetery.

Joe Louis Barrow (1914-81)

Nicknamed the brown bomber, Barrow was a heavyweight icon in the 1930s and 1940s. The day after he raised $47,000 for a Navy relief charity event, he enlisted in the Army during World War II.

Medgar Evers (1925-1963)

Evers served during World War II and was a key player in desegregating the University of Mississippi.

Thurgood Marshall (1908-93)

Famous for arguing the 1954 Brown v. Board of Education case, Justice Marshall was the first African-American associate justice of the Supreme Court.

Matthew Henson (1866-1955)

Henson was the first African-American to reach the North Pole and plant the American flag. In 1988, by presidential order, Henson's remains were moved to Arlington National Cemetery.

Pierre Charles L'Enfant (1754-1825)

(Photo: Josh/Wikipedia)

L'Enfant was the architect who designed the layout of Washington, D.C. His design included the National Mall and Pennsylvania Avenue, the road that connects the Capitol and White House. When he first arrived in America, he joined the Army in the Revolutionary War.

Glenn Miller (1904-1944)

Miller was a famous big band leader in the swing era. He was serving in the Army Air Corps band en route to visit U.S. troops in France during World War II when his plane disappeared in bad weather over the English Channel. While his body is still missing, Miller's daughter arranged for a headstone to be placed at Arlington.

Robert Peary (1856-1920)

A former naval officer, Peary was the leader of the 1909 expedition that was the first to reach the North Pole.

Charles "Pete" Conrad (1930-99)

Capt. Conrad was a naval aviator, aeronautical engineer, test pilot and astronaut. He was the third man to walk on the moon and part of the second group of aviators accepted into NASA's space program.

Adolphus Greely (1844-1935)

(Wikipedia)

Maj. Gen. Greely served in the U.S. Army during the civil war. He founded the National Geographic Society and was an explorer who survived two Arctic winters without being resupplied in 1881. Greely was awarded the Medal of Honor at age 91.

Marguerite Higgins (1920-66)

A Pulitzer Prize-winning journalist, Higgins was the only female war correspondent during the Korean War.

Helen Herron "Nellie" Taft (1861-1943)

Helen, the wife of President Taft, arranged for the planting of 3,000 Japanese cherry trees that surround the Tidal Basin today.

Earl Warren (1891-1974)

(Wikipedia)

Warren was a three-time governor of California, vice presidential candidate, presidential candidate and 16-year chief justice. He led the Warren Commission, which investigated the assassination of President Kennedy, and served in World War I as an Army lieutenant.