The collection contains professional and personal correspondence of James B. Eads with Edward Bates, Gideon Welles, Gustavus Fox, Henry Taylor Blow, Frank P. Blair, Jr., Baron Gerolt, and others. Includes papers relating to Eads' construction of gunboats during the Civil War and the construction of the Illinois and St. Louis Bridge (also known as the Eads Bridge). The collection also includes 20th-century newspaper clippings regarding James B. Eads and relations; cancelled stock certificates in the Tunnel Railroad of St. Louis and the St. Louis Bridge Company; invitations to the opening of the Illinois and St. Louis Bridge; promissory notes; Eads' scrapbook of newspaper clippings (1881) relating to his plan to build a ship railway across the Isthmus of Tehuantepec; and papers relating to the genealogy of the McHenry family.