[1] During his career, Saunders designed the Soldiers National Cemetery at Gettysburg, planned and developed the Washington D.C. park system, introduced numerous new plant species into the United States, and authored many articles on horticulture.

In addition to managing the estate farm, Saunders designed landscape features including large lakes and various flower gardens.

In addition to establishing a nursery, Saunders and Meehan collaborated on several public park projects, cemeteries, and residential site plans.

Saunders laid out the cemetery on a radial plan focused on a central monument, and grouped the Union dead by states [citation needed].

"[1] Around the cemetery, Saunders framed the site with extensive plantings, using uncommon varieties of trees and shrubs, many of which he had recently introduced to America himself.

Saunders later wrote that "He [Lincoln] was much pleased with the method of the graves, saying it differed from the ordinary cemetery, and after I had explained the reasons, said it was an admirable and befitting arrangement.

His design featured large open areas of lawn and irregular groupings of non-native trees including magnolias, arbor vitae, and mock orange.

[5] His guidelines called for the USDA to procure new and better plants for the country and “ascertain, by experiment, the influences of varied culture” and “investigate more thoroughly the various maladies and diseases of plants and the insects that destroy them.”[5] As example of their productivity, in two years from 1865 to 1867, the USDA Experimental Garden evaluated more than 120 wheats, 167 ryes, 230 melon varieties, 70 peas, 50 grass species for hay production, and more than 500 strawberries, grapes, apples, and pears.

With Tappahannock, wheat distributed by the department showed an average yield per acre of twenty-five bushels.”[5] The navel orange was Saunder's most acclaimed plant introduction.

Saunders presented two of the trees to an old friend, Eliza Tibbets, who left Washington, D.C., to join her husband in the new community of Riverside, California.