Johns Hopkins' views on his bequests, and on the duties and responsibilities of the two boards of trustees, especially the hospital board of trustees led by his friend and fellow Quaker Francis King, were formally stated primarily in four documents, the incorporation papers filed in 1867, his instruction letter to the hospital trustees dated March 12, 1873, his will, which was quoted from extensively in his "Baltimore Sun" obituary, and in his will's two codicils, one dated 1870 and the other dated 1873.