Neptune's windy atmosphere in August 1989. The ice giant Neptune was the first planet located through mathematical predictions rather than through regular observations of the sky.
well slavery was an big issue because it separated the northern and southern states. the northern states realize that slavery was an unnessary inhumane treatment and wanted to abolished it. While the southern states depended on slaves since they worked for free on their plantation. To resolve this they counted 3 free men for 5 slaves until 1808.
The issue of slavery ultimately did tear the Union apart, but 74 years before the start of the Civil War this volatile issue threatened to do the same during the Constitutional Convention when Northern and Southern states took strong positions on the issue. Those who opposed slavery in the Northern states wanted to bring an end to the importation and sale of slaves.