Final answer:
The correct cause-and-effect relationship is more jobs in factories leading to the migration of African Americans from the South to northern cities as they sought to escape racism and find economic opportunities during the Great Migration.
Step-by-step explanation:
The pair of circumstances that represents an accurate cause-and-effect relationship is A) more jobs in factories --> migration of African Americans from the South to northern cities. This is due to both "push" factors, such as the intense racial hatred and violence in the South, and "pull" factors, like the economic opportunities presented by industries and factories in the North. The Great Migration saw a significant movement of African Americans out of the South to seek better lives and escape the oppressive Jim Crow segregation laws. While this move provided opportunities, African Americans still faced many challenges, including discrimination and loss of jobs post-war, when soldiers returned home.
Other options B, C, and D do not accurately reflect cause-and-effect relationships from history. The Dred Scott decision preceded the Fugitive Slave Law and did not directly cause its passage, the closing of the frontier was not a direct cause for the completion of the transcontinental railroad, and the establishment of Jim Crow laws came after the beginning of Reconstruction, not as a cause of it.