Donau-Schwarzmeer-Kanal
Following the idea of the British diplomat David Urquhart, in 1844 Ionescu developed and supported the proposal for the building of an artificial waterway across the Ottoman province of Dobruja, located between the Danube and the Black Sea (Port of Constanța). His proposal aimed to support the transportation of the increasing cereal production of the Danubian Principalities toward the seaport of Kustendje (today Constanța in Romania) for the mutual profit of the Romanian grain producers and Ottoman (mainly Ottoman Greeks and Ottoman Armenians) and foreign merchants. The Danube–Black Sea Canal and its additional waterworks where completed only in 1987.