Republic of Texas
In 1824, with the newly-independent Mexican government wishing to settle its mostly-empty northern region, Moses Austin was invited to settle a colony of Americans in east Texas. The settlers were given certain civil guarantees (and implicitly assured that a blind eye would be turned to slavery, illegal in Mexico). Many Americans came.
However, when the dictator Santa Anna came to power, he rescinded these guarantees and threw Stephen F. Austin (son of Moses Austin) in prison when he protested. Led by General Sam Houston, the American settlers declared independence in the Texas War of Independence.
The government was modeled off that of the United States, with executive, legislative (divided into a House and Senate), and judicial departments. Despite the absence of subordinate state governments, Congress's powers were limited similar to those of the United States Congress. The law code was to be "the common law of England, with such modifications as our circumstances, in [Congress's] judgment, may require". The President, with similar powers to the President of the United States, was to be elected by direct popular vote for three years.
Slavery was specifically permitted, citizenship was limited to "free white persons," and emancipation was forbidden unless the former slaves were sent out of Texas.
Presidents of Texas
According to the Constitution, the first President would serve for two years, subsequent Presidents would serve for three years, and no one could succeed himself.
- David Burnet, Interim President (March 1836-October 1836)
- Sam Houston (October 1836-December 1838)
- Mirabeau Lamar (December 1838-December 1841)
- Sam Houston (2nd Administration) (December 1841-December 1844)
- Anson Jones (December 1844-February 1846)
On December 29, 1845, President James K. Polk signed the Joint Resolution of Congress declaring Texas annexed. However, the Republic of Texas government continued until February 19, when Governor J. Pinckney Henderson was officially inaugurated. 
Several Texan groups have declared themselves the legitimate government of the Republic of Texas, asserting that it was never legally abolished, since the United States annexed it by a joint resolution instead of by international treaty. In addition, a 2009 poll said that 18% of Texans would vote to secede from the United States.
- Constitution of the Republic of Texas, full text