Why was the United States willing to pay more per mile for the Gadsden Purchase than for the Mexican Cession?

They were willing to pay more because the purchase allowed them to have more land in order to build the railroad.

the group i'm selecting: greeks.

a first group of greek immigrants came to the us in the 1850s. the second group came to america starting in the 1890s due to economic opportunities they didn't have back in their home caused by the hardships of ottoman rule. greek immigration was 90% male, many of them expected to work and return to greece after earning enough capital, but ultimately had to remain in the us after the greek genocide.