How did the Texan Republic begin its history

Although Mexico's war of independence pushed out Spain in 1821, Texas did not remain a Mexican possession for long. It became its own country, called the Republic of Texas, from 1836 until it agreed to join the United States in 1845. Sixteen years later, it seceded along with 10 other states to form the Confederacy.

Explanation:

In 1835, the central government split Texas and Coahuila into two separate departments.On March 1, 1836 the Convention of 1836 came to order, and the next day declared independence from Mexico, establishing the Republic of Texas.

Explanation:

both include an amendment process.

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