April 16th is Emancipation Day in Washington D.C.

Most people know that the tax deadline is extended until tomorrow this year. But why?

April 16 is a local holiday in Washington, D.C. -- Emancipation Day -- which is the day in 1862 when President Abraham Lincoln signed a declaration freeing 3,100 slaves living in Washington. The president's action happened nearly nine months before Mr. Lincoln signed the Emancipation Proclamation, which freed slaves in ten Confederate States.  This year, which marks the 150th anniversary of the signing of the Compensated Emancipation Act, includes ceremonies and parades with civil rights leaders Jesse Jackson and Rev. Al Sharpton, religious leader Reverend Joel Osteen and local officials.
Slaves played key roles in the development of a young nation's capital. They cleared the land of trees for the Capitol, built it and played a major role in constructing its expansion in 1850. They also helped to build the White House, too.

Here are the dates of emancipation celebrations across the country and the world.

• Puerto Rico-- March 22 is Puerto Rico's official Emancipation Day holiday.
• Mississippi-- This state celebrates on May 8, also known as "Eight o' May."
• Florida-- The holiday is May 20, the day the Emancipation Proclamation was read in the state in 1865.
• Texas-- June 19, commonly known as "Juneteenth," commemorates the announcement of the abolition of slavery there in 1865.
• U.S. Virgin Islands-- July 3 is the official Emancipation Day, commemorating the day that Gov. Peter Von Scholten abolished slavery in 1848.
• Kentucky-- August 8 marks the day that Kentucky's slaves learned of their freedom.
• Canada-- Ontario celebrates its Emancipation Day on the first Monday in August, commemorating the abolition of slavery in Upper Canada in 1810. The Slavery Abolition Act of 1833 officially ended slavery in the British Empire and thus the rest of Canada.
• Barbados-- The "Season of Emancipation" is April 14 to August 23.
• Bermuda-- Bermuda usually celebrates on August 2 with the first day of "Cupmatch," a cricket competition.
• The Bahamas-- Celebrations are primarily held in a former slave village in Nassau, where residents apparently heard about their freedom a week later than everyone else on the island.
• In many other countries, such as Trinidad and Tobago, Saint Kitts and Nevis, and Anguilla, Emancipation Day celebrations take place during Carnival.