[4] In the years 1875-1876 he made a study trip to Germany as a scholarship holder of the General Staff.

From 1879 to 1883, Gadd was a teacher of warfare and military history at the Royal Swedish Army Staff College.

[3] In 1880, Gadd was promoted to major in the General Staff and he served as Vice Chief of the Military Office of the Ministry of Land Defence from 1880 to 1883.

[1] Gadd was promoted to major general in 1892 and four years later, on 16 January 1896, he was appointed commander of the 4th Army Division, succeeding Crown Prince Gustaf on the post.

[3] In addition to its military activities, Gadd was chairman of the executive board of the Royal Central Gymnastics Institute from 1894 to 1909,[3] of the Court-Martial of Appeal from 1903 to 1910[9] and of the Executive Board of the Army Pension Fund (Arméns pensionskassa) from 1905[1] and the King's Hospital (Konungens hospital).