Take some time to formulate your search terms. Are you looking for an event, legal case, political organization [Tet Offensive, Detroit Riots, Plessy v. Ferguson, Black Panther Party] or legislation [Wiretapping Act of 1968, which is officially know as the Omnibus Crime Control and Safe Streets Act of 1968] or a specific era [Reconstruction, Harlem Renaissance, “Jim Crow”]. Keywords will lead you to more topics to help you narrow your search:
United States -- Social conditions -- 1865-1918; Southern States -- Social conditions -- 1865-1945; United States -- Race relations -- History -- 19th century; Southern States -- Race relations -- History -- 19th century; Reconstruction (U.S. history, 1865-1877) -- Social aspects; Reconciliation -- Social aspects -- United States -- History; African Americans -- Social conditions -- 19th century; Women --
For PRIMARY SOURCES, try your subject terms PLUS a combination of these terms:
primary sources, digital library, oral history, repository, photographs, digital humanities, visualization, archive, FINDING AID, images, film, ephemera, broadside
Online Historical Resources: Library of Congress, US National Archives, US State Archives, and National Archives (UK). Also local and state historical societies.
College & University Digital Collections (with search term digital collection or digital library), more University Library Resources