Final answer:
Frederick Douglass perceived the Dred Scott decision as proof of the Slave Power's influence and a challenge to Republican anti-slavery expansion efforts, deepening national divisions.
Step-by-step explanation:
Frederick Douglass recognized that one effect of the Dred Scott decision on the nation was to galvanize the Republican Party's opposition to slavery's expansion and expose the extent of the Slave Power within the federal government. The decision rendered the Republican goal of preventing the spread of slavery into territories unconstitutional, exacerbating sectional strife and undermining northern Democrats' position on popular sovereignty. It also solidified southern confidence in the legality of slavery throughout the United States and exacerbated regional divisions.
The Dred Scott decision had a significant impact on the nation. One effect of the decision was that it further ignited anger and frustration among Republicans. The ruling not only declared that African Americans could never be citizens, it also asserted that Congress had no power to restrict the expansion of slavery into the territories. This decision led to the deepening divide between the North and the South, strengthening the pro-slavery sentiment in the South and fueling the growing anti-slavery sentiment in the North.