He returned to South Africa in 1881 during the First Boer War (1880–1881) where he served as private secretary for the then vice-president Paul Kruger.

In 1887, he accepted the position of judge to the criminal court of the South African Republic which had been offered to him by Kruger the previous year.

In 1894, he was appointed to the position of State Attorney of the South African Republic but resigned after one year and returned to private practice.

After the war he maintained an active interest in politics, becoming one of the founders the Het Volk party which advocated for self-government.

[2] Ewald Esselen died in 1918 at Sea Point in Cape Town and is buried in the Ou Begrafplaas in Pretoria.