I am pretty sure the answer is D. 21st
The main way in which the creation of new states changed the political boundaries of the great plains was that each state had to have borders, that were usually based around rivers.
The Civil Rights Movement racked up many notable victories, from the dismantling of Jim Crow segregation in the South, to the passage of federal legislation outlawing racial discrimination, to the widespread awareness of the African American cultural heritage and its unique contributions to the history of the United States. African Americans fought back with direct action protests and keen political organizing, such as voter registration drives and the Mississippi Freedom Democratic Party. The crowning achievements were the Civil Rights Act of 1964 and the Voting Rights Act of 1965.
The answer is "Back country".
The western third of the state of Pennsylvania in the US is referred to as Western Pennsylvania. Pittsburgh is the district's key city, with a metropolitan region populace of around 2.4 million individuals, and fills in as its financial and social focus.
Fun fact: Pennsylvania is also known as the "Bread Basket" of America :)
