William & Mary Libraries have hundreds of database, each with a different focus. Sabin America is great for historical printed material like books, pamphlets, and short printed material. Colonial America has letters and correspondences. America's historical Imprints have broadsides, adverts, and announcements. American History 1493-1945 has books, maps, art.
It can take a long time to decide which databases to use, however it is worth your time to read the descriptions and select the databases most likely to contain the type of material you need.
Words change meaning over time.
When selecting search terms in a database, be sure to use contemporary terms avoid anachronisms.
If I'm interested in concepts of gender in the Atlantic World, I'd need to find another word for "gender"
To get a topics of gender, I might try other words like: Masculinity, Femininity, Manliness, or Unmasculine
Substitute modern words or terms with phrases from that time period. For example:
"food" instead of "foodways"
"atlantic trade" instead of "columbian exchange"
"massacre" instead of "genocide"
"transportation" instead of "convicts"
"Indian" or "Native" instead of "Indigenous"
Be mindful, too, Europeans were not always careful or nuanced in their use of native names for places, peoples, or individuals. French trappers might, for example, call all Native Americans "Algonquins" in their writing, even if they were in fact Montagnais, Huron, or any other number of Native American groups
TIP: After your first couple searches, pay attention to the language being used in your search results. Even if the results aren't spot-on, this is a good way to determine the types of language contemporaries used to describe your topic.
Fight the urge to use a lot of search terms at once.
Instead, select two or three carefully selected keywords, search for them with AND between each word.
If you get too many results, use the "publication date" function to narrow the results.
If you add too many search terms, you'll accidentally miss results.
Don't rush and don't settle. It can take time to find the best search terms, and it takes time to find the best database. Sometimes even perfect search terms simply won't work in a database because of the type of material it contains. Be patient, be methodical, and give yourself time to search multiple databases. The exact same search in equally-excellent databases may yield wildly different results.