Who was the youngest president? Here's what to know about the man on Mount Rushmore.

Since the nation's founding the United States has had 46 presidents. Twenty-one states have been the birthplace of presidents with Virginia producing the most at eight  including George Washington, Thomas Jefferson and James Madison.

President Richard Nixon is the only president to resign from office, following his involvement in the Watergate Scandal. Three presidents have been impeached, with President Donald J. Trump being impeached twice, but none have been removed from office, according to History.com.

These are all good facts about the presidents to know, but have you ever wondered who the youngest president was?

Just curious?: We're answering your everyday questions

Who was the youngest president?

According to The White House, the youngest person to have ever served as president was President Theodore Roosevelt.

Roosevelt, who was the 26th president from 1901 to 1909, was 42 years and 322 days old when he assumed the office of the presidency on Sept.14, 1901, according to World Atlas.

Roosevelt became president after the assassination of President William McKinley on Sep. 6, 1901, according to History.com.

As president Roosevelt became known as a “trust-buster” after his successful attempt using the Sherman Anti-Trust act, which had previously been ineffective, to break up the Northern Securities Company, a railroad combination, according to History.com.

The Northern Securities Company had formed a railroad monopoly that violated the Sherman Anti-Trust act, according to Constitutional Law Reporter.

The Sherman Anti-Trust Act declared combinations "in the form of trust or otherwise that was in restraint of trade or commerce among the several states, or with foreign nations" illegal, according to the National Archives. Under the Sherman Act the federal government was authorized to "institute proceedings against trusts in order to dissolve them."

According to the White House, he is also known for getting the U.S. more involved in World politics and for repeating a favorite proverb of his, “Speak softly and carry a big stick.”

According to the White House, as the 35th president, President John F. Kennedy, was the youngest person ever elected president. Kennedy was 43 years and seven months old in 1961 when he became president, according to the Constitution Center. Kennedy was also the youngest president to die in office after he was assassinated in 1963.

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Who was the oldest president?

According to World Atlas, the oldest person to serve as president of the U.S. is President Joe Biden, the 46th. At 78 years and 61 days old at the time of his inauguration, Biden was almost eight years older than the second oldest president of the U.S., President Donald J. Trump, who was 70 years and 220 days old when he was sworn in.

At 78 years-old when he was sworn in President Joe Biden is the oldest person to serve as president.
At 78 years-old when he was sworn in President Joe Biden is the oldest person to serve as president.

How old do you have to be to be president?

Article 2 section I of the Constitution says to be eligible to hold the office of the president an individual must be 35 years old. The Constitution also says an individual must be a natural born citizen and must have been a resident of the U.S. for the last 14 years.

Who is the oldest person to have run for president?

According to Oldest.org, at 85 years, one month and 27 days old during the time of the election Harold Stassen, the 25th governor of Minnesota, was the oldest person to have ever run for president. Born April 13, 1907, and died March 4, 2001, Stassen sought the Republican nomination for president nine times between 1948 and 1992, according to the University of Pennsylvania Archives. But he never won the nomination to represent his party.

This article originally appeared on USA TODAY: Who is the youngest president? He is immortalized on Mount Rushmore.