American Battlefield Protection Program Amendments Act of 2026 This bill extends through FY2036 three National Park Service (NPS) grant programs that preserve U.S. battlefields and requires the NPS to study additional sites for potential preservation. Specifically, the bill extends through FY2036 grant programs for the acquisition, interpretation modernization, and restoration of certain U.S. battlefields. (Under current law, the grants are authorized through FY2028.) The bill also requires the NPS to prepare or certify studies of locations tied to significant events during the French and Indian War (1754-1763) and the Mexican-American War (1846-1848) for potential preservation.