As noted earlier, W&M Libraries has a LOT of primary source databases.
The reason we have so many different primary source databases is because they all do different things and cover different time period.
Some are full of old scanned booked published before 1800.
Some are scanned collections of letters.
Others are full of newspapers and broadsides.
Others are government and trade records.
It's unlikely that any 1 database will meet all your needs, so it's important to spend a bit of time search several of them.
Read the database summaries to see what each contains, and to decide if it relates to your topic.
Keep your searches basic, no more than 2 or 3 keywords. Then limit those results by publication, location, type.
Use Period-Specific terms.
Wide range of material (correspondence, journals, notes, etc)
PRINTED MATTER (BOOKS, BROADSIDES, ETC)
Magazines and Popular Periodicals
Government Records
HISTORIC NEWSPAPERS
Plantation Records