Chikungunya fever is caused by a virus spread by infected mosquitoes. In recent years, cases have been reported in parts of Asia and the Indian Ocean. Source: CDC

Any donations to Haiti relief efforts made this year (by Feb. 28) can be taken as a deduction against 2009 taxes. Source: IRS

Thomas Jefferson was the first president to deliver a "State of the Union" message in writing, instead of personally before a joint session of Congress. Subsequent presidents followed suit, until 1913, when President Woodrow Wilson made the speech in person.  Source: Congressional Research Service

The opposition party’s response to the State of the Union address began in 1966 when Republican Sen. Everett Dirksen of Illinois and Republican Rep. Gerald R. Ford of Michigan delivered the rebuttal to President Lyndon Johnson’s speech.  Source: Office of the Clerk of the U.S. House

The "State of the Union address" was formally known as the "Annual Message" from 1790 until 1934. Source: Office of the Clerk of the U.S. House

Article II, Section 3, Clause 1 of the U.S. Constitution authorizes the president to deliver information on the "State of the Union" to Congress.  Source: U.S. Constitution

On this day in 1890, reporter Nellie Bly greeted a crowd in New York 72 days, 6 hours, 11 minutes and 14 seconds after setting sail east to circle the globe. Source: Library of Congress

On this day in 1848, James W. Marshall discovered gold near Coloma, California. The discovery was officially endorsed by President James Polk in December that year, launching the Gold Rush. Source: Library of Congress

The 24th Amendment to the U.S. Constitution, which prohibited the collection of poll taxes in national elections, was ratified on this day in 1964. Source: Library of Congress

On this day in 1912, Key West, Florida, became linked to the Florida peninsula by the Florida East Coast Railway; the overseas railway was destroyed by a hurricane 23 years later. Source: Library of Congress