What does a "sectional split" in the US Senate mean?

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Explanation:

region over those of a country as a whole. Throughout American history, tension has existed between several regions, but the competing views of the institution of slavery held by Northerners and Southerners was the preeminent sectional split and the defining political issue in the United States from the founding of the country until the American Civil War.

gave common people the right to vote

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