A primary source is any record contemporary to an event or time period. Primary sources may be written, oral, visual or physical. Some of these sources were produced with the intent of being preserved for the future. Such intentional sources include government documents, church records, autobiographies or memoirs. On the other hand, many primary sources were produced without any intent of future use. Such unintentional sources may include private correspondence not originally meant for posterity but which later are deposited in archives and libraries. Physical evidence such as buildings, clothing, tools, and landscapes may also be labeled as unintentional sources.
--Galgano, Michael J., J. Christopher Arndt, and Raymond M. Hyser. Doing History: Research and Writing in the Digital Age. Cengage Learning, 2007, p. 57.
Letters & diaries published as books can be found in the UM LIBRARIES CATALOG by adding keywords:
Provides access to full-text letters & diaries by North American women from colonial times to 1950. This collection includes the immediate experiences of 1,325 women and 150,000 pages of diaries and letters.
Contains searchable PDF's of materials published in Colonial America and the early U.S. such as books, pamphlets, and broadsides. The collection may be browsed by topic (e.g., Genre: Songs, Economics: Liquor Traffic, History: Louisiana Purchase,etc.)
Contains English-language titles and editions based on the English Short Title Catalogue, made available online over the course of the next two years.
Images and full-content access to historic newspapers from the 18th to mid-19th Century, based on the collections of the American Antiquarian Society, the Wisconsin Historical Society, and 90 other institutions, from every region of the United States.
There are certain words that appear in the subject headings of items in the UM LIBRARIES CATALOG that constitute primary sources. The most important of them is sources, but there are others.
In the simple keyword search box, you can put such words after SU: in order to specify the SUBJECT field.
ex.: trail of tears and SU:sources
In the advanced keyword search, you can put your search term(s) in the top box, and in the second box, put the word(s) you're using to locate primary sources in the next box, and change the drop-down menu to Subject:
Keywords that will help you find primary sources:
Depending on the period being studied, it can also be helpful to limit your search by publication date.
More keywords identifying primary sources in Library of Congress Subject Headings
To find the papers of a historically prominent individual, use the Advanced MERLIN Search. Use the first line to specify the author (surname first, e.g., Lincoln, Abraham) and the second line to specify papers in the title. You can also use the Advanced search to combine any of the above primary source oriented keywords with a particular author.
For further information about state and federal government sources, see the guides to Federal Government Documents, Missouri Government Documents, and the Primary Sources By Decade page. For Britain and foreign governments that were part of the British Empire, see the Parliamentary Papers guide.
Contains bibliographic records and digitized pages of every publication from the orgininal print volumes issued between 1832 and 1861. Enables searching and browsing of legislative and executive documents of the first 14 U.S. Congresses.
The single most comprehensive source of treaties and other international agreements to which the United States has become a party. In addition, includes law and law-related periodicals.
Presents the numerical history of the United States. It contains annual time series of quantitative historical information covering virtually every quantifiable dimension of American history, all from the earliest times to the present.
A Topical Index of Early U. S. Almanacs, 1776-1800 by 
