Final answer:
Eleanor Roosevelt's resignation letter had a profound impact, exemplifying her commitment to civil rights and equality, and influencing public opinion and political discourse on these crucial issues.
Step-by-step explanation:
The impact of Eleanor Roosevelt's resignation letter was significant and multi-faceted. Her actions and strong stance on various issues, including civil rights and women's rights, signaled to the public and to other political leaders that she was deeply committed to these causes. This resonated with many Americans who shared her vision for a more equitable society. Roosevelt's choice to resign from the Daughters of the American Revolution (DAR) over their decision not to allow Marian Anderson to perform at Constitution Hall was a powerful statement against racial discrimination and for the advancement of civil rights. As a renowned public figure, Eleanor Roosevelt's decision garnered widespread media attention and further highlighted the societal issues she was combating.