Many of the battlefields have been built over and are now lost. Another is about to be lost though the Civil War Trust is fighting to save it. Read about this at : http://www.campaign1776.org/take-action/speak-out/princeton/letter-from-jim-lighthizer.html
December 13, 2016 update:
Friends:
It gives us great pleasure to share with you the following announcement, made available to the press at midnight, that the Institute for Advanced Study has agreed to terms for the sale of the critical Maxwell’s Field property on the Princeton battlefield so it can be preserved and interpreted for the benefit of the American people. The American Revolution Institute is proud of its role in reaching this important milestone. Pessimists said it couldn’t be done. Like Washington’s officers, we ignored the skeptics and fought on. This is the kind of important work our organization was created to do.
Best regards,
Jack D. Warren, Jr.
Executive Director
The American Revolution Institute of the Society of the Cincinnati13
Minnesota SAR 