Which event occurred last

a The Joint Resolution

bThe Mier Expedition

The Treaty to Annex Texas

d. The Morfit Report

The Treaty to Annex Texas-1845-1848

Explanation:

The treaty to Annex Texas was a process of making Texas a part of the United States and it involves series of steps and processes and occurred between 1845-1848 thereby making it the event that occurred last.

The Morfit Report was the first event to occur in 1836, followed by the Mier Expedition in 1842 then the Joint Resolution occurred in 1845.