Most people know Aaron Burr for being the second vice president of the United States and for killing Alexander Hamilton in a duel, but he had grander designs for his life.
When Aaron Burr looked at a map of North America, instead of Spanish possessions he saw a Western empire expanding to the Pacific, and if the United States were (yes 'were', United States was not usually treated as singular until after the Civil War,) not interested in making that a reality, he would do the job himself.
In 1806, just a year out of office, he purchased land in the Baron de Bastrop's grant near Natchitoches, Louisiana. From there he would launch his invasion of Texas, the first step in his plan to conquer Mexico.
But General James Wilkinson, the United States military governor of the just acquired Louisiana territory, got wind of Burr's plans and sent world to authorities in Kentucky where the former VP was recruiting.
In Kentucky, Burr was tried twice for planning an illegal expedition, but was acquitted both times. Burr never stopped recruiting and in 1808 set sail from Nashville with his party of 'colonists'.
Thomas Jefferson wasn't buying it. He knew Burr's eye was on lands West of the Sabine and had him arrested for treason.
Burr was tried before the Supreme Court, Chief Justice John Marshall presiding. The verdict: not guilty, as the Constitution required that and act of treason must be overt and witnessed by two people.
Jefferson was furious and challenged the Supreme Court's authority in the case. He was ready to string Burr up on an executive conviction.
The trial put an end to Burr's Texas ambitions and he fled to Europe ahead of his creditors.
Given the state of Spanish governance at the time, there is a very real chance he may have succeeded had Jefferson not intervened. In that case, Aaron Burr would have been the father of Texas.