Look at the green shaded part of the first map then explain how the u. s gained all that land from the border to the pacific ocean?

The idea of the us gaining all land from one seaboard to the other is called manifest destiny the us gained these lands through several different purchases, annexations, and agreements such as the annexation of texas the treaty to give the us land in oregon below the 49th parallel and so forth. 

Hey the answer is the politics of the southern united states generally refers to the political landscape of the southern united states. due to the region's unique cultural and historical heritage, including slavery, the south has been involved in many political issues. some of these issues include states' rights, reconstruction, the civil rights movement and social conservatism. from the 1870s to the 1960s, the region was referred to as the solid south, due to their consistent support for democrats in all elective offices. as a result, its congressmen gained seniority across many terms, thus enabling them to control many congressional committees. in presidential politics, the south began to move away from national democratic loyalties with the dixiecrat movement of 1948 and the barry goldwater presidential campaign of 1964. among white southerners, democratic loyalties first fell away at the presidential level, followed much later at the state and local levels.