Was Texas one of the slave-holding states?

From the early seventeenth through mid-nineteenth centuries, millions of African people were captured and transported to the Americas to be sold as slaves. Many of these people were purchased as a source of essentially free labor throughout the colonies which developed into the United States of America. 

In the Southern colonies, especially, society surrounded the agricultural industry. The most well-to-do colonists were ones with lots of land, lots of crops, and lots of slaves. Crops...

From the early seventeenth through mid-nineteenth centuries, millions of African people were captured and transported to the Americas to be sold as slaves. Many of these people were purchased as a source of essentially free labor throughout the colonies which developed into the United States of America. 

In the Southern colonies, especially, society surrounded the agricultural industry. The most well-to-do colonists were ones with lots of land, lots of crops, and lots of slaves. Crops which were in high demand in Europe, like tobacco, cotton, and sugar, were often farmed through slave labor. The Industrial Revolution and a booming trade-based economy drove the demand for slave labor into the hundreds of thousands of "new" slaves per year. Depending on the crops being raised in differing areas of the South, and the legality of owning slaves in these areas, the distribution of slave labor varied.

The Texas territory changed hands many times during the legacy of American slavery, and because of this it took a longer time for slave labor to become established there. From at least 1821, when Moses Austin founded a new Anglo-American colony in Texas, slavery was imported as an institution with the arrival of new white families. Slave labor in Texas was used to farm cotton and sugarcane. Slavery formally ended in Texas on the 19th of June, 1865.