The annexation of the Republic of Texas by the United States of America occurred in 1845 after US President Polk
called a joint session of Congress to approve Texas's annexation into the Union, and it passes by a slim margin due to anti-slavery critics in the Congress not wanting to see the expansion of slavery and southern power into the Western portions of North America.
The Margin was so slim however that if a few more Northern state legislatures had voted against the Annexation, Texas would never have been annexed. So what if the Northern states ordered their delegations to Congress to vote against the Annexation of Texas, and Texas doesn't get annexed by United States, surviving as an independent nation into the 1900's and beyond?
Well, my fellow Wikians, you are about to find out.