April 9, 1939: African-American singer Marian Anderson performs before 75,000 people at the Lincoln Memorial in Washington, D.C., after having been denied the use both of Constitution Hall by the Daughters of the American Revolution, and of a public high school by the federally controlled District of Columbia.

August 2, 1939: Albert Einstein wrote to President Franklin Roosevelt about developing the atomic bomb using uranium.
This led to the creation of the Manhattan Project.

September 5, 1939: World War II: The United States declares its neutrality in the war.

November 4, 1939: World War II: President Roosevelt ordered the United States Customs Service to implement the Neutrality Act of 1939, allowing cash-and-carry purchases of weapons to non-belligerent nations.

November 15, 1939: President Roosevelt laid the cornerstone of the Jefferson Memorial.

April 1, 1940: April Fools' Day was also the census date for the 16th U.S. Census.

May 16, 1940: World War II: President Roosevelt, addressed a joint session of Congress, asking for an extraordinary credit of approximately $900 million to finance construction of at least 50,000 airplanes per year.

June 10, 1940: World War II: President Roosevelt denounced Italy's actions with his "Stab in the Back" speech during the graduation ceremonies of the University of Virginia.

August 4, 1940: World War II: Gen. John J. Pershing, in a nationwide radio broadcast, urges all-out aid to Britain in order to defend the Americas, while Charles Lindbergh speaks to an isolationist rally at Soldier Field in Chicago.

September, 1940: The Army's 45th Infantry Division (previously a National Guard Division in Arizona, Colorado, New Mexico, and Oklahoma), was activated and ordered into federal service for 1 year, to engage in a training program in Ft.
Sill and Louisiana, prior to serving in World War II.

September 2, 1940: World War II: An agreement between America and Great Britain was announced to the effect that 50 U.S. destroyers needed for escort work would be transferred to Great Britain.
In return, America gained 99-year leases on British bases in the North Atlantic, West Indies and Bermuda.

September 26, 1940: World War II: The United States imposed a total embargo on all scrap metal shipments to Japan.

October 16, 1940: The draft registration of approximately 16 million men began in the United States.

October 29, 1940: The Selective Service System lottery was held in Washington, D.C..
November 5, 1940: U.S. presidential election, 1940: Democrat incumbent Franklin D. Roosevelt defeated Republican challenger Wendell Willkie and became the United States's first and only third-term president.

November 12, 1940: Case of Hansberry v. Lee, 311 U.S. 32 (1940), decided, allowing a racially restrictive covenant to be lifted.

December 17, 1940: President Roosevelt, at his regular press conference, first  outlined his plan to send aid to Great Britain that will become known as Lend-Lease.

December 29, 1940: Franklin D. Roosevelt, in a fireside chat to the nation, declared that the United States must become "the great arsenal of democracy."

January 13, 1941: All persons born in Puerto Rico after this day were declared U.S. citizens by birth, through federal law 8 U.S.C. § 1402.

January 20, 1941: Chief Justice Charles Evans Hughes swore in President Roosevelt for a third term.

January 27, 1941: World War II: U.S. Ambassador to Japan Joseph C. Grew passed on to Washington a rumor overheard at a diplomatic reception about a planned surprise attack upon Pearl Harbor, Hawaii.

February 4, 1941: World War II: The United Service Organization (USO) was created to entertain American troops.
April 9, 1939: African-American singer Marian Anderson performs before 75,000 people at the Lincoln Memorial in Washington, D.C., after having been denied the use both of Constitution Hall by the Daughters of the American Revolution, and of a public high school by the federally controlled District of Columbia.
August 2, 1939: Albert Einstein wrote to President Franklin Roosevelt about developing the atomic bomb using uranium. This led to the creation of the Manhattan Project.
September 5, 1939: World War II: The United States declares its neutrality in the war.
November 4, 1939: World War II: President Roosevelt ordered the United States Customs Service to implement the Neutrality Act of 1939, allowing cash-and-carry purchases of weapons to non-belligerent nations.
November 15, 1939: President Roosevelt laid the cornerstone of the Jefferson Memorial.
April 1, 1940: April Fools' Day was also the census date for the 16th U.S. Census.
May 16, 1940: World War II: President Roosevelt, addressed a joint session of Congress, asking for an extraordinary credit of approximately $900 million to finance construction of at least 50,000 airplanes per year.
June 10, 1940: World War II: President Roosevelt denounced Italy's actions with his "Stab in the Back" speech during the graduation ceremonies of the University of Virginia.
August 4, 1940: World War II: Gen. John J. Pershing, in a nationwide radio broadcast, urges all-out aid to Britain in order to defend the Americas, while Charles Lindbergh speaks to an isolationist rally at Soldier Field in Chicago.
September, 1940: The Army's 45th Infantry Division (previously a National Guard Division in Arizona, Colorado, New Mexico, and Oklahoma), was activated and ordered into federal service for 1 year, to engage in a training program in Ft. Sill and Louisiana, prior to serving in World War II.
September 2, 1940: World War II: An agreement between America and Great Britain was announced to the effect that 50 U.S. destroyers needed for escort work would be transferred to Great Britain. In return, America gained 99-year leases on British bases in the North Atlantic, West Indies and Bermuda.
September 26, 1940: World War II: The United States imposed a total embargo on all scrap metal shipments to Japan.
October 16, 1940: The draft registration of approximately 16 million men began in the United States.
October 29, 1940: The Selective Service System lottery was held in Washington, D.C..
November 5, 1940: U.S. presidential election, 1940: Democrat incumbent Franklin D. Roosevelt defeated Republican challenger Wendell Willkie and became the United States's first and only third-term president.
November 12, 1940: Case of Hansberry v. Lee, 311 U.S. 32 (1940), decided, allowing a racially restrictive covenant to be lifted.
December 17, 1940: President Roosevelt, at his regular press conference, first  outlined his plan to send aid to Great Britain that will become known as Lend-Lease.
December 29, 1940: Franklin D. Roosevelt, in a fireside chat to the nation, declared that the United States must become "the great arsenal of democracy."
January 13, 1941: All persons born in Puerto Rico after this day were declared U.S. citizens by birth, through federal law 8 U.S.C. § 1402.
January 20, 1941: Chief Justice Charles Evans Hughes swore in President Roosevelt for a third term.
January 27, 1941: World War II: U.S. Ambassador to Japan Joseph C. Grew passed on to Washington a rumor overheard at a diplomatic reception about a planned surprise attack upon Pearl Harbor, Hawaii.
February 4, 1941: World War II: The United Service Organization (USO) was created to entertain American troops.
76th United States Congress