The following year, the trustees of the estate announced a design competition for the library, and Eames & Young of St. Louis submitted the winning proposal.

[5][6][7] The Rosenberg Library added the Moody Memorial Wing in 1971, doubling the size of the building and re-orienting the entrance to the Sealy Avenue side.

Kempner, Harris Kempner, Henry M. Trueheart, and J. C. League; the records of several organizations and churches in the area; and 20th-century collections reflecting recent events and activities in Galveston and the upper Gulf Coast.

Holdings of the museum department include historical artifacts pertaining to Galveston or early Texas, paintings of Galveston subjects or by local artists including Julius Stockfleth and Boyer Gonzalez, and a sizable collection of Russian and Greek icons.

The rare book collection contains incunabula, first editions, and examples of fine printing.