Answer:
They grazed cattle to make the land ready for farming
Step-by-step explanation:
Texas is a very large state (the second largest in the U.S. after Alaska), and it has different climates and biomes. In general terms, the East is wetter and more suitable for farming, while the West is dry and more suitable for cattle.
In east and central texas, settlers would use cattle to graze the land, and make it suitable for farming, and depending on how east or west of the state they were, they also used irrigation systems to make the land more suitable for growing crops.