 Some of the original 1898 buildings still exist and now house the Thoreau Center for Sustainability.The Letterman Army Medical Center built in the 1960s era was completely demolished to make way for Letterman Digital Arts Center.The hospital, built in 1898 and named in 1911 for Major Jonathan Letterman, MD (1824–1872), was featured in every US foreign conflict in the 20th century and remained in service until the army base was decommissioned in 1995.