NDNP awardee states are selected incrementally, chosen every two years in "Phases". Each Phase is defined by a date range. Phase I (2005-2007) limited content to a single decade 1900-1910; Phase II (2007-2009) included content from 1910 back to 1880; and Phase III (2009-2011) opened the field to include dates 1860 through the copyright ceiling of 1922.

The University of Kentucky Libraries was one of only six institutions selected during NDNP Phase I along with University of California-Riverside, University of Florida — who has since dropped out of the program — New York Public Library, University of Utah, and Library of Virginia. The Library of Congress adds content from Distict of Columbia newspapers. Only one institution from each state or territory is, or will ever be, responsible for NDNP content submission, though inter-state partnerships are permitted to assist in adding content.

Phase II introduced several new awardees to the NDNP family of contributors. They are Minnesota Historical Society, University of Nebraska - Lincoln, and University of North Texas.

In June 2008, a third round of awardees were introduced bringing the total contributing states to sixteen. They are Arizona Department of Libraries, Archives and Public Records, Ohio Historical Society, Pennsylvania State University, State Historical Society of Missouri, University of Hawaii, Manoa, and Washington State Library.

Phase III commenced in July 2009 with the inclusion of seven more awardee states: University of Illinois - Urbana, Kansas State Historical Society, Louisiana State University, Montana Historical Society, Oklahoma Historical Society, University of Oregon, and the University of South Carolina. There are now 22 states and the District of Columbia contributing content to Chronicling America.

In July 2010 three new awardee states were added to the program: University of New Mexico, University of Tennessee, and University of Vermont. There are now 25 states and the District of Columbia contributing content to Chronicling America.

In 2011, yet three more states were added to the program: Indiana State Library, North Dakota, and West Virginia University. These bring Chronicling America content to include 28 states and the District of Columbia.

2012 brought into the program State Historical Society of Iowa, University of Maryland, Collage Park, Central Michigan University, and the University of North Carolina, Chapel Hill. These bring Chronicling America content to include 33 states and the District of Columbia.