Why was the building of transcontinental railroads so significant in causing the development of the USA in the later nineteenth century?

Describe the geography of the nile valley . how did this geography affect civilizations that emerged in the nile valley

Why were presidents andrew jackson and martin van buren unwilling to annex texas? a. they did not want texas to be admitted to the union as a slave state. b. they feared that the annexation of texas as a slave state would lead to political problems within the union. c. they thought that texas was too large to be admitted to the union as one state. d. they did not believe in the idea of manifest destiny.

True or false president andrew johnson granted pardons to thousands of southerners.