Antarctica, an immense continent, wasn't seen by humans until the early 19th centuary.
David Rice Atchison (1807-1886) was president of the United States for one day, according to some historians. But that claim is challenged by others.
President James K. Polk's term finished March 3, 1849, and March 4 was to be inauguration day for the 12th U.S. president, Zachary Taylor.
But since that day was a Sunday, the inauguration was postponed until the next day. So techincally, the United States had no president on March 4.
Atchison, as president of the Senate, was next in line for the office, and some authorities say he was actually president for that day.
Atchison, a senator from Missouri, was elected Senate president 16 times between 1846 and 1854.
Stevens of Hoboken
Inventor John Stevens (1749-1838) served in the Revolutionary War and later became tresurer of New Jersey.
Stevens owned and operated the ferry from Hoboken to New York City and in 1788 built the first multitubular marine boiler which he patented.
In 1802, he devised a steamboat with underwater screw propellers. His vessel, the Phoenix, made the first voyage by steamship on ocean waters. Stevens was also a railroad pioneer. In 1815, he obtained America's first railway charter and in 1832 completed the first rail route across New Jersey, operated by his sons. Stevens Institute of Technology in Hoboken, opened in 1871, was endowed by his son, Edwin.