One of the main things that motivated the Founding Fathers to include the phrase "to form a more perfect union" in the Preamble of the U.S. Constitution is because they knew that things like slavery and other impaired citizens rights would have to be eliminated someday.
I am pretty sure that it was James Madison.
The Texas Revolution (October 2, 1835 – April 21, 1836) was a rebellion of colonists from the United States and Tejanos (Texas Mexicans) in putting up armed resistance to the centralist government of Mexico. While the uprising was part of a larger one that included other provinces opposed to the regime of President Antonio López de Santa Anna, the Mexican government believed the United States had instigated the Texas insurrection with the goal of annexation. The Mexican Congress passed the Tornel Decree, declaring that any foreigners fighting against Mexican troops "will be deemed pirates and dealt with as such, being citizens of no nation presently at war with the Republic and fighting under no recognized flag." Only the province of Texas succeeded in breaking with Mexico, establishing the Republic of Texas, and eventually being annexed by the United States.
The revolution began in October 1835, after a decade of political and cultural clashes between the Mexican government and the increasingly large population of American settlers in Texas. The Mexican government had become increasingly centralized and the rights of its citizens had become increasingly curtailed, particularly regarding immigration from the United States. Colonists and Tejanos disagreed on whether the ultimate goal was independence or a return to the Mexican Constitution of 1824. While delegates at the Consultation (provisional government) debated the war's motives, Texians and a flood of volunteers from the United States defeated the small garrisons of Mexican soldiers by mid-December 1835. The Consultation declined to declare independence and installed an interim government, whose infighting led to political paralysis and a dearth of effective governance in Texas. An ill-conceived proposal to invade Matamoros siphoned much-needed volunteers and provisions from the fledgling Texas army. In March 1836, a second political convention declared independence and appointed leadership for the new Republic of Texas.
https://www.arcgis.com/apps/MapJournal/index.html?appid=409ac58e8dff4a71b427c2d85e151945
What was a factor keeping Europeans out of interior Africa until the late 1800s?
Disease
Rough ground
Dangerous animals
