The period from the late 1700s (upheavals preceding and including the American Revolution) to 1850 (first US census that aimed to name every person) could be called the "Dark Ages" in US genealogy. Many of the records we rely on for research after 1850 didn't exist then, or existed only in bare-bones form.
To put it another way, before 1850 is where we see the final breakdown of the dubious idea that genealogy is just a matter of "looking up" your ancestors in the records. Those accustomed to doing that kind of genealogy may find the pre-1850 research environment bewildering.
Of course it's not barren, just different. But we do need to know where to look, and what to look for. The first step is to change our attitude:
- look for clues (indirect evidence), not only direct statements;
- search as much by area or associates as by name;
- pay more attention to the historical context (emphasized in the course I took at the Genealogical Research Insitute of Pittsburgh on the Northern part of this topic), especially since the past gets weirder the further back we go; and
- don't yield quickly to the temptation of trying to "connect" with a likely-looking individual in 1760.
- land records (federal, state, local), including tax records;
- probate records;
- military records;
- any post-1850 records that cast light backwards into the Dark Age (such as a late-life marriage application, or an obituary that tells more than the death certificate, or a grandchild's mug book entry);
- unsourced books and online trees (with appropriate caution);
- newspapers (advertisements much more than obituaries) and early ephemera (called "imprints");
- court records; and
- manuscript collections, including business records. (In western New York, as Josh Taylor will explain if you give him an opening, the early land records often are business records.)
Photo credit: J. C. Loudon, (1826) An encyclopædia of agriculture (London: 1826, 2nd edition 1831), figure 512, "Trenching"; digital image, Flickr (http://www.flickr.com/photos/marceldouwedekker/7468901744 : viewed 11 August 2013), Maarcel Douwe Dekker's photostream, per Creative Commons.
Harold Henderson, "Shedding light on the Dark Age of American genealogy," Midwestern Microhistory: A Genealogy Blog, posted 12 August 2013 (http://midwesternmicrohistory.blogspot.com : viewed [date]). [Please feel free to link to the specific post if you prefer.]