Question

Why was the first treaty of annexation not good for Texas

Answer 1

Most likely because shortly after Texas's becoming a union state led to war with Mexico, likely causing the death of many Texans

Answer 2

There's more, just type in Texas State historical association>mga02

The annexation of Texas to the United States became a topic of political and diplomatic discussion after the Louisiana Purchase in 1803 and became a matter of international concern between 1836 and 1845, when Texas was a republic. In September 1836 Texas voted overwhelmingly in favor of annexation, but when the Texas minister at Washington, D.C., proposed annexation to the Martin Van Buren administration in August 1837, he was told that the proposition could not be entertained. Constitutional scruples and fear of war with Mexico were the reasons given for the rejection, but antislavery sentiment in the United States undoubtedly influenced Van Buren and continued to be the chief obstacle to annexation. Texas withdrew the annexation offer in 1838; President Mirabeau B. Lamar (1838–41) opposed annexation and did not reopen the question. Sam Houston, early in his second term (1841–44), tried without success to awaken the interest of the United States.