This primary source comes from the Records of the Public Buildings Service.
Full Citation: 'Columbia Under the Palm' Princeton, NJ Post Office Mural by Karl Free; 1935 - 1943; Painting: North Carolina, North Dakota, New Jersey, New Hampshire, New Mexico; Completed Murals and Sculptures in United States Post Offices and other Federal Buildings, 1935 - 1943; Records of the Public Buildings Service, Record Group 121; National Archives at College Park, College Park, MD. [Online Version, https://www.docsteach.org/documents/document/columbia-under-the-palm-princeton-nj-post-office-mural, May 11, 2024]