Every American student learns that Christopher Columbus sailed the ocean blue and landed in the New World in 1492. Winifred Sackville Stoner, Jr.'s poem "History of the U.S." has made it impossible to forget the date (although the couplet actually predates her birth), and many workers get a day off of work every October to celebrate the explorer's exploits. You know the who and where, but here are 10 more answers to pressing questions about Columbus Day.

1. WHEN DID COLUMBUS BECOME A CULTURAL ICON?

By the early 1500s, other figures like Amerigo Vespucci and Francisco Pizarro had become more popular and successful than Columbus had been with his off-course voyages. According to The New York Times, historians and writers in the latter part of the 16th century restored some of Columbus’s reputation with great words of praise for the explorer and his discoveries, with his fellow Italians proving particularly eager to celebrate his life in plays and poetry.

2. HOW DID THAT POPULARITY REACH THE UNITED STATES?

Blame the British. As the American colonies formed an identity separate from their English roots, colonists looked to figures like the "appointed of God" Columbus to symbolize their ideals. "By the time of the Revolution," writes John Noble Wilford, "Columbus had been transmuted into a national icon, a hero second only to Washington." Columbus's American legacy got another shot in the arm in 1828 when a biography (peppered with historical fiction) by Washington Irving transformed Columbus into an even more idealized figure who sought to "colonize and cultivate," not to strip the New World of its resources.

3. WHEN WAS THE FIRST COLUMBUS DAY?

The first recorded celebration took place in 1792 in New York City, but the first official holiday held in commemoration of the 1492 voyage coincided with its 400th anniversary in 1892. President Benjamin Harrison issued a proclamation in which he called Columbus a "pioneer of progress and enlightenment" and suggested that Americans "cease from toil and devote themselves to such exercises as may best express honor to the discoverer and their appreciation of the great achievements of the four completed centuries of American life."

If Harrison had had his way, though, the holiday would have been celebrated on October 21. He knew that Columbus landed under the Julian calendar, not the Gregorian calendar we use today—making October 21 the correct date for anniversary celebrations.

4. DID ANYONE ACTUALLY CELEBRATE COLUMBUS DAY IN THE 19TH CENTURY?

Italian Americans embraced Columbus as an important figure in their history and, according to historians, saw celebrating him as a way to "be accepted by the mainstream." The Knights of Columbus, an organization formed by Irish-Catholic immigrants in 1882, chose the Catholic explorer as their patron "as a symbol that allegiance to their country did not conflict with allegiance to their faith." Following President Harrison’s 1892 proclamation, they lobbied for Columbus Day to become an official holiday.

5. SO WHEN DID IT BECOME AN OFFICIAL HOLIDAY?

The holiday first found traction at the state level. Colorado began celebrating Columbus Day, by governor proclamation, in 1905. Angelo Noce, founder of the first Italian newspaper in the state, spearheaded the movement to honor Columbus and Italian-American history. In 1907, the Colorado General Assembly finally gave in to him and made it an official state holiday.

6. WHEN DID IT BECOME A FEDERAL HOLIDAY?

With Franklin D. Roosevelt as president, lobbying from the Knights of Columbus paid off, and the United States as a whole observed Columbus Day in 1934. Thirty-four years later, Lyndon B. Johnson signed the Uniform Holiday Bill, which designated Columbus Day as a federal holiday.

7. WHY DOES THE DATE CHANGE EVERY YEAR?

Columbus Day was originally celebrated on October 12, the day Columbus landed in the New World, but the Uniform Holiday Bill took effect in 1971 and changed it to the second Monday in October, as well as moving the dates of Washington’s Birthday, Memorial Day, and Veterans Day to Mondays (Veterans Day would be moved back to November 11 in 1980 after criticism from veterans’ groups). The act of Congress was enacted to "provide for uniform annual observances of certain legal public holidays on Monday, and for other purposes."

8. DOES EVERY STATE OBSERVE THE HOLIDAY ON THE SAME DAY?

In Tennessee, Columbus Day comes with an asterisk. The state’s official holiday observance calendar reads that Columbus Day is the second Monday of October, or "at the Governor's discretion, Columbus Day may be observed the Friday after Thanksgiving."

9. WHICH STATES DON'T CELEBRATE COLUMBUS DAY?

In Hawaii, the second Monday of October is known as Discoverer’s Day, "in recognition of the Polynesian discoverers of the Hawaiian Islands, provided that this day is not and shall not be construed to be a state holiday." According to Pew Research Center, only 23 states and the District of Columbia treated Columbus Day as a paid state holiday in 2013. South Dakota celebrates Native Americans Day as an official state holiday, and several cities like Seattle and St. Paul, Minnesota celebrate Indigenous People's Day.

10. HOW DO OTHER PLACES AROUND THE WORLD CELEBRATE COLUMBUS DAY?

In Italy, Columbus Day (or Giornata nazionale di Cristoforo Colombo) is listed as one of the national or international days of celebration and is still on October 12, but it's not a public holiday. Some countries have chosen to observe anti-Columbus holidays like the "Day of the Indigenous Resistance" in Venezuela and Nicaragua, "Pan American Day" in Belize, and the "Day of Respect for Cultural Diversity" in Argentina.