Were the Grimke sisters right to participate in the abolitionist movement in the way that they did?Imagine that you are an American living in the...

The question you pose also asks for moral and philosophical judgments.  Were the Grimke sisters "right" to participate ...

A lot would depend on the criteria used to evaluate what was right.  Assuming basic Constitutional principles would apply as a starting point, the Grimke sisters exercised their first amendment right to free speech, free association, and freedom of press.  They were nonviolent in their approach.

One might argue that John Brown was not right in that he used violence as a means to achieve political goals, and did so outside the framework of legal government.  For the Grimkes there was no similar behavior to judge them and their actions on.