Bartolomeu Dias was the first sailor
One of the ways in which the Northwest Ordinance of 1787 had an impact on westward expansion in the United States was that "<span>It established procedures for how territories could become states," which had huge implications for the future os slavery. </span>
Answer: Slavery played the central role during the American Civil War. The primary catalyst for secession was slavery, especially Southern political leaders' resistance to attempts by Northern antislavery political forces to block the expansion of slavery into the western territories.