The bibliography The Published Diaries and Letters of American Women (Seymour Library Reference: CT3260 G66 1987) lists published sources for letters and diaries in chronological fashion. The annotations accompanying the citations are robust, and therefore will give a very good sense of the content and context for the memoirs. To get the texts you want to use:
Look carefully at the footnotes and bibliographies in secondary sources for references to primary sources. Texts published before 1929 are likely to be digitized and available in either HathiTrust or in the Internet Archive. For example, the text highlighted in the footnote here is available in both HathiTrust and the Internet Archive.
The Knox Library has a few published collections of documents on Open Reserve in Seymour Library. Highlights of the published primary sources on Reserve:
In addition, the Open Reserves collection for the course contains several primary sources written by individual women. To see more titles on Reserve, click here.
There are numerous autobiographical works freely available online in full text because they are published before 1929. Below is a list of some of these kinds of works. The texts are usually in pdf.
Searchable collections of early printed books are available at the Text Creation Partnership. The Partnership provides free access to millions of page images from two important collections: Eighteenth Century Collections Online, and Evans Early American Imprints. Search each collection separately:
The Evans collection contains thousands of items published in America from 1470-1790 including books, pamphlets and broadsides.
Eighteenth Century Collections Online is a collection of book, pamphlet, and ephemera material published in England during the 18th century, along with thousands of books printed in America.