After he was president, who described himself as the greatest opponent of southern slavery that the world had ever seen?
To find out who described themselves as the greatest opponent of southern slavery after their presidency, you can follow these steps:
1. Start by conducting a search using a search engine such as Google or Bing.
2. Enter relevant keywords into the search query, such as "former president greatest opponent of southern slavery."
3. Review the search results and look for credible sources such as historical websites, biographies, or reputable news outlets.
4. Look for information related to the statements or declarations made by former presidents regarding their opposition to southern slavery.
5. Pay attention to the context and credibility of the sources to ensure the information is accurate and reliable.
Using this method, you should be able to find the answer to your question.