[3] After serving as district engineer at the expanding ports of Los Angeles and Galveston, he was selected by Brigadier General George W. Goethals as an assistant in the construction of the Panama Canal, on which he worked from 1907 to 1911.

[4] Upon the country's entry into World War I, he recruited the 15th Engineers, a railway construction regiment, and led it to France to join the American Expeditionary Forces (AEF).

He directed American construction and forestry work there for a year and received the Army Distinguished Service Medal, the citation for which reads: The President of the United States of America, authorized by Act of Congress, July 9, 1918, takes pleasure in presenting the Army Distinguished Service Medal to Brigadier General Edgar Jadwin, United States Army, for exceptionally meritorious and distinguished services to the Government of the United States, in a duty of great responsibility during World War I.

Later, in charge of the Division of Construction and Forestry, he brought to this important task a splendidly trained mind and exceptionally high skill.

His breadth of vision and sound judgment influenced greatly the successful completion of many vast construction projects undertaken by the American Expeditionary Forces.

[4] The Vicksburg, Mississippi district of the Army Corps Of Engineers operates a large inland river dredge named after Edgar Jadwin.

[6][7] Source:[8] Jadwin received the Army Distinguished Service Medal,[5] the Companion Order of the Bath from Great Britain, and the Commander in the Legion of Honour from France.