The Archive of Americana provides access to Readex's collections of newspapers and government publications. Specifically, the Archive of Americana includes the following Readex collections:

America's Historical Newspapers
American State Papers, 1789-1838
House and Senate Journals, Series I, 1789-1817
Senate Executive Journals, 1789-1980
The Civil War: Antebellum Period to Reconstruction
U.S. Congressional Serial Set

The inclusion of the above collections under one umbrella makes it possible to search these collections simultaneously.