Nathan Hale was an American soldier, Patriot, and spy who worked for the Continental Army. He played an important role during the American Revolutionary War, volunteering for an intelligence-gathering mission. Nathan Hale was captured and executed by the British in 1776. Hale is regarded as an American hero for his important contribution during the American Revolutionary War.
E. Howard Hunt was an American author and intelligence officer. He is best remembered for his service in the Central Intelligence Agency from 1949 to 1970, during which he served as an officer. E. Howard Hunt was part of the White House Special Investigations Unit during the presidency of Richard Nixon.
Robert Hanssen is a former FBI agent who was convicted of spying against the U.S., for the Russian intelligence agencies. Hanssen reportedly sold countless classified documents containing U.S. nuclear and military strategies. He pleaded guilty to avoid the death penalty. He eventually received 15 life sentences, without parole.

Ethel Rosenberg was an American citizen who was convicted along with Julius Rosenberg of spying in favor of the Soviet Union. Ethel and Julius were convicted of passing top-secret information about sonar, radar, valuable nuclear weapon designs, and jet propulsion engines to the Soviet Union. Julius and Ethel Rosenberg were executed by the American government in 1953.
Clyde Tolson was an American associate director of the FBI from 1930 to 1972. He is perhaps best remembered for his relationship with FBI Director J. Edgar Hoover; it has been speculated that Clyde Tolson shared an intimate relationship with Hoover.
Aldrich Ames is a former CIA officer who later became a KGB double agent. He was convicted of spying and is currently serving a life sentence. He allegedly worked as a Soviet spy and revealed classified CIA data. He inspired the 1998 film Aldrich Ames: Traitor Within.
Peggy Shippen was a spy who was active during the American Revolution. She was the highest-paid spy and worked alongside her husband General Benedict Arnold, who started conspiring with the British in the late-1770s. Peggy Shippen's role in the conspiracy was exposed in September 1780, when British Major John André was captured by the Americans.

Sidney Gottlieb was an American spymaster and chemist who played a major role in the CIA's mind-control program and assassination attempts during the 1950s and 1960s; the illegal human experimentation program which he headed was called Project MKUltra.

Theodore Hall was an American physicist. He was one of the atomic spies for the Soviet Union during World War II. Hall gave a detailed description of a plutonium bomb named Fat Man to the Soviet Union. He also passed on vital information such as the processes involved for purifying plutonium. His life inspired a documentary titled A Compassionate Spy.
James Armistead Lafayette was an enslaved African American. He is best remembered for his service in the Continental Army during the famous American Revolutionary War, where he worked under the command of a French aristocrat and military officer named Lafayette. He worked as a double agent, feeding the British with wrong information and disclosing accurate information to the Americans.

David Greenglass was an atomic spy who worked for the Soviet Union. He was part of the Manhattan Project and was also stationed at the Clinton Engineer Works, a uranium enrichment facility in Tennessee. David Greenglass' testimony helped convict his brother-in-law Julius and his sister Ethel Rosenberg.

Noshir Gowadia is a former design engineer. A convicted spy for several countries, Gowadia was indicted for selling classified information to individuals in Switzerland, Germany, and Israel and to China. Noshir Gowadia received a 32-year prison sentence in 2011.

Frank Sturgis was an American spy who worked as an undercover agent for the Central Intelligence Agency. He was counted among the five Watergate burglars whose arrest led to the end of Richard Nixon's presidency. Frank Sturgis served in multiple branches of the US military. He also served in the Cuban Revolution of 1958.

Edwin P. Wilson was a former CIA officer who was convicted of illegally selling weapons to Libya in 1983. He also served as an officer in the Office of Naval Intelligence before his conviction. However, his convictions were overturned in 2003 and Edwin P. Wilson was freed in 2004.
Belle Boyd was a Confederate spy who was active during the American Civil War. Operating from her father's hotel in Virginia, Boyd provided key information to Confederate Commander Stonewall Jackson in 1862. Belle Boyd's life and career inspired a series of silent films called The Girl Spy.

Miles Copeland, Jr. was an American businessman, musician, and Central Intelligence Agency officer. He is remembered for his close friendship with Gamal Abdel Nasser and his famous books on intelligence. Miles Copeland, Jr. played important role in the March 1949 Syrian coup d'état as well as in the 28 Mordad coup d'état, participating in many covert operations in the process.

Rose O'Neal Greenhow was a well-known Confederate spy who was active during the American Civil War. She is credited with securing the South's victory at the Battle of First Manassas in July 1861. After her demise, Rose O'Neal Greenhow was given a Confederate military funeral.

American abolitionist Elizabeth Van Lew is best-known for developing and running an extensive and efficient spy-ring for Union Army during American Civil War. She was the first person in Richmond who raised the US flag in the city after it fell to US forces in April 1865. She later served as Postmaster General of Richmond and modernized the city's postal-system.

Legendary heroine of the American Revolutionary War, Nancy Hart was a skilled frontierswoman and herbalist from Georgia. Folklore has it that she was a 6-feet tall, muscular, red-headed woman, known as “war woman” to the locals. She is said to have fought and spied dressed as a man.

Canadian-born Sarah Emma Edmonds is best-remembered as the woman who served the Union Army, disguised as a man, during American Civil War. She also claimed that she served as a spy. She later used her real identity and served as a nurse at a hospital in Washington, D.C. In 1897, Edmonds was admitted to the Grand Army of the Republic.

Confederate soldier Sam Davis, who was captured, convicted and executed by Union forces at just 21 years of age in Pulaski, Tennessee, during the American Civil War, is remembered for his courage and loyalty and lauded as the Boy Hero of the Confederacy. A martyr to the Confederate cause, Davis was eulogized by Middle Tennesseeans for his bravery and sacrifice.

Irish woman Lydia Darragh is said to have saved George Washington’s Continental Army from a British attack during American Revolutionary War. She eavesdropped on a secret conference of British officers quartered in her house and after learning about the impending attack on the Continental army camped at White Marsh, she delivered the information and saved Washington's army from an ambush.

Edward Bancroft was a Massachusetts-born chemist and physician. He played an important role during the American Revolution, working as a double agent for both Great Britain and the United States. Edward Bancroft's activity as a double agent wasn't disclosed until 1891, when diplomatic papers were made public knowledge by Great Britain.

John Honeyman was a British informant and American spy for George Washington, the first president of the United States. His primarily duty was to spread disinformation. John Honeyman also gathered the intelligence that facilitated George Washington's triumph in the Battle of Trenton.

American detective Lafayette C. Baker who served the Union Army during the American Civil War, is also remembered for his espionage activities. He apparently spied on the Confederate Army for General Winfield Scott. However, in spite of heading the Union intelligence forces, he was sacked for allegedly spying on President Andrew Johnson.

American spy Herbert Philbrick worked for the FBI and conducted intelligence operations on the Communist Party in the US. While working for the Massachusetts Youth Council, he suspected them of having Communist links and soon began spying on them for the government. He later penned the bestseller I Led Three Lives.

American secret agent Ralph McGehee worked for the CIA for over 2 decades. Chiefly known for his fight against Communism, he worked in various Asian and South East Asian countries, such as Vietnam. His book Deadly Deceits later revealed some of the most glaring flaws of the CIA.
Democratic Party member Benjamin Thomas Wolf, who ran for and lost the election to the 5th Congressional District of Illinois, has also worked with the FBI. He has also been a professor in Chicago. He was known as the Cannabis Candidate, as he promised to legalize cannabis if he won.

Robert J. Lamphere worked as an agent for the FBI and helped the US counter some the most notorious intelligence attacks, including the Soviet espionage strategy that threatened to wreck the Manhattan Project, leading to the arrest of many Soviet spies. Post-retirement, he headed the Veterans Administration as a deputy administrator.