Abolitionists wanted the Dred Scott case to be heard by the courts because this would bring slavery to the forefront and Congress would be forced to deal with the issue. Why? Well, see below for an explanation!
Let’s start by addressing what the Dred Scott case was and how it affected former slaves and blacks as a whole. The Dred Scott v. Sanford case was a situation that occurred during the times of slavery (year of 1857). Dred Scott’s slave owner passed away and Scott offered that he buy his freedom. The Chief Justice in court at the time sought an opportunity to settle that blacks were inferior. When the case was heard in Supreme Court, the ruling came out explicitly that black people were inferior and had no rights as far as the white man. Under these circumstances, it was implied that Dred Scott could not purchase his freedom as could a white man. Abolitionists also saw this as an opportunity though because they wanted the conflict of slavery to be addressed publicly and with a straightforward response/resolution. If you need any extra help, let me know and I will gladly assist you.