Hello there! The most significant and lasting legacy from the presidency of James K. Polk was vast land acquisitions.
James K. Polk was the 11th president of the United States of America. During his term, Polk proposed his idea of what is called “Manifest Destiny,” which meant that whites were destined to expand America and conquer lots of territory, as the answer states.
He was responsible for tempers that happened, the expansion of the United States, and Manifest Destiny. One temper problem that occurred during his time of presidency was the Irish Potato Famine, which was a period of Irish immigration into the United States to avoid the famine and starvation. Polk also signed the Treaty of Guadalupe-Hidalgo, which ended the Mexican-American War by bringing California and New Mexico into the United States.
Your final answer: The most significant and lasting legacy from the presidency of James K. Polk would be B (vast land acquisitions). If you need any extra help, let me know and I will gladly assist you.