A Similarity search allows you to check for alternate or similar spellings for your search term. This is especially useful for searching historical documents, since word usage and spelling conventions have changed over time. The search results page will return a list of words with a similar spelling to the term, each with a check-box. If you would like to see the documents where these terms occur, click in the box to make a checkmark, and then hit the 'Search' button. This search will not work with numbers, punctuation, or wildcards.
Example of search for Wisconsin: