The Union League of Philadelphia   

Heterodox Academy

The Organization of American Historians

Academic Freedom Association

Easttown Township (Pennsylvania) Planning Commission (2000-2004)

Board of Directors, The Abraham Lincoln Association (2000- present)

Board of Directors, The Abraham Lincoln Institute (1998- 2019); president 2013-2014

Gilder Lehrman Institute of American History board of trustees

Gilder Lehrman Lincoln Prize Advisory Council

Appointee of President George W. Bush, on the National Council for the Humanities from 2006 to 2012

National Council on the Humanities

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