Final answer:
The period between 1836 and 1845 was significant for Texas as it formed the Republic of Texas and saw political tensions regarding its annexation to the United States. This period also ultimately led to the Mexican-American War.
Step-by-step explanation:
The period between 1836 and 1845 was a significant time in Texas history as it marked the formation of the Republic of Texas and the events leading to its annexation to the United States. After gaining independence in 1836, Texas remained an independent nation until 1846. During this time, Texas saw an influx of American immigrants and political tensions with Mexico regarding annexation. The annexation of Texas ultimately played a role in the Mexican-American War.