Examples of Primary Sources

Infant Mortality

Secondary Source: Smith, Billy. "Death and Life in a Colonial Immigrant City: A Demographic Analysis of Philadelphia." Journal of Economic History, Vol. 37, No. 4 (Dec. 1977), pp. 863-889.
Primary Source: Samuel Cobb tomb at West Tisbury Village Cemetery, Martha's Vineyard.

Secondary Source: Schafer, Judith Kelleher. "New Orleans Slavery in 1850 as Seen in Advertisements." Journal of Southern History, Vol. 47, No. 1 (Feb. 1981), pp. 33-56.
Primary Source: July 25, 1774 advertisement from the George Washington Papers at the Library of Congress. See also 1847 advertisement from African American Odyssey at the Library of Congress.

Secondary Source: Theodore Roosevelt: Icon of the American Century, an exhibit at the National Portrait Gallery.
Primary Source: Diary entry for Feb. 14, 1884, Feb. 16, Feb. 17 Part of American Treasures of the Library of Congress.