Which U.S. state was the last to join the Union?

Hawaii is indeed recognized as the last U.S. state to join the Union, achieving statehood on August 21, 1959. This means it became the 50th state of the United States. The process of Hawaii's admission involved extensive political negotiations and symbolic significance, as it was the final addition to the United States after a long history of territorial status since its annexation in 1898.

Alaska, which joined the Union on January 3, 1959, was the second-to-last state to gain statehood; thus, it is not the correct answer. Texas, which joined in 1845, holds a notable place in U.S. history but was far earlier in terms of statehood compared to Hawaii. California was admitted in 1850, also long before Hawaii. Understanding the timeline of state admissions is crucial for grasping the history of the U.S. territorial expansion and governance.