This collection includes correspondence to and from Boskovic; a travel journal in Europe; and a large number of manuscripts on astronomy, hydrography, hydro-mechanics, mathematics, geometry, mechanics, and optics; and a volume of poetry.

The manuscripts of father William Mitchell and daughter Maria Mitchell are not easily separated, and are treated here together. The collection includes William Mitchell's autobiography, his memoir of Judge Walter Folger of Nantucket, astronomical and meteorological observations, lectures, family and other correspondence.