Why should enslavement have been prohibited in the territory that the United States took from Mexico after the Mexican American war?

Look at the map of cities in the united states at the turn of the twentish century what impact did railroads have on cities across the united states at the turn of the twentish century

Which statement best describes a major advantage of a confederal system of government over a unitary system

Plz , ive been stuck on this forever. what action did president jefferson take to stop britain and france from seizing american merchant ships. a. he declared war on france. b. he called for increased tariffs on british and french goods. c. he called for embargo on all foreign trade. d. he declared war on britain.