Humanities Homework Help

I don’t know how to handle this History question and need guidance.

What was “Manifest Destiny”? How did the policies of James K. Polk, 1845–1849, realize the dreams of American expansionists in those years? What were the consequences of the Mexican–American War? Discuss the sectional crisis of 1850. What were the elements of the compromise reached by the north and the south that year?