A Treatise on the Theory and Practice of Landscape Gardening: Online text of the book by A.J. Downing, published in 1859, from Making of America Books.
Andrew Jackson Downing: An illustrated biography by Christopher Glynn Parker of one of the most important pre-Civil War designers and writers in America.
Downing, Andrew Jackson: Brief biography from the Columbia Encyclopedia, Sixth Edition (2001).
Downing, Andrew Jackson (1815-1852): A brief article and web links from Noted Relations on this American horticulturalist, nurseryman, architect and landscape architect.
The Architecture of Country Houses: Online text of the book by A. J. Downing with 320 illustrations, which was published in 1859. From Making of America.