 He failed to be elected to the Constituent Assembly that drafted the grand duchy's first Constitution in 1848.However, he was subsequently elected to the Chamber of Deputies, which the Constitution established and which succeeded the Constituent Assembly, representing Echternach from 1848 to 1854 and Clervaux from 1854.Eyschen became a minister as Director-General for Justice in the administration of Charles-Mathias Simons.