Free access to the ArchiveGrid database has been extended until June 30 (previously, it was until May 30). The web site describes the offerings:
ArchiveGrid is an important destination for searching through historical documents, personal papers, and family histories held in archives around the world.
Thousands of libraries, museums, and archives have contributed nearly a million collection descriptions to ArchiveGrid. Researchers searching ArchiveGrid can learn about the many items in each of these collections, contact archives to arrange a visit to examine materials, and order copies.
There are unique resources in this site. I perused the site two months ago for several hours, but found little new information on my ancestral families. However, there might be a real gem or two for YOURS.
Note that if you find an item of interest, you need to contact the repository to obtain a copy or more information about the actual document.