He then returned to Moldavia and was involved in the conspiracy of 1848, which was intended to bring about the union of Wallachia and Moldavia under one native prince Mihai Sturdza. The conspiracy failed and Ion Ghica became a lecturer on mathematics at the university which was founded by Prince Sturdza in Iasi.
In 1848 he joined the party of revolution and in the name of a provisional government then established in Bucharest went to Constantinople to approach the Turkish government. Whilst there he was appointed Bey of Samos (1853-1859), where he extirpated piracy, rampant in that island.
In 1859 after the union of Moldavia and Walachia had been effected Prince Cuza asked John Ghica to return. He was the first prime minister under Prince (afterwards King) Carol of Hohenzollern. His restless nature made him join the anti-dynastic movement of 1870-1871.
Besides his political distinction Ion Ghica earned a literary reputation by his Letters to Alecsandri, his lifelong friend, written from London and describing the ancient state of Romanian society, fast fading away. He was also the author of Amintiri din pribegie ("Recollections of Exile") in 1848 and of Convorbiri Economice, discussions on economic questions. He was the first to advocate the establishmentof national industry and commerce, and also, to a certain extent, principles of exclusive dealing.