Why was there a court case about Dred Scott?

The case of Dred Scott v. Sandford was first heard by the Supreme Court on February 11–14, 1856, and reargued on December 15–18, 1856. Dred Scott’s lawyers reiterated their earlier argument that because he and his family had resided in the Louisiana territory, Scott was legally free and was no longer enslaved.

The Dred Scott case, also known as Dred Scott v. Sandford, was a decade-long fight for freedom by a Black enslaved man named Dred Scott. The case persisted through several courts and ultimately reached the U.S. Supreme Court, whose decision incensed abolitionists, gave momentum to the anti-slavery movement and served as a stepping stone to the Civil War.

Explanation:

https://www.history.com/topics/black-history/dred-scott-case

abraham lincoln  (february 12, 1809  – april 15, 1865) was an american statesman, politician, and lawyer who served as the 16th  president of the united states  from 1861 until  his assassination  in april 1865. lincoln led the nation through the  american civil war, its bloodiest war and its greatest moral, constitutional, and political crisis.[2][3]  he preserved the  union,  abolished slavery, strengthened the  federal government, and modernized  the u.s. economy.

explanation:

hitler's  "rise" can be considered to have ended in march 1933, after the reichstag adopted the enabling act of 1933 in that month. president paul von hindenburg had already appointedhitler  as chancellor on 30 january 1933 after a series of parliamentary elections and associated backroom intrigues.