In the 1850s (after the Crimean War), Focșani grew in importance as the center of activities in favor of the union between Wallachia and Moldavia (the Danubian Principalities), leading to the double election of Alexandru Ioan Cuza in Iași and Bucharest.
In 1944, during World War II, Focșani was supposed to be part of the fortified Focșani-Nămoloasa-Galați line, where 9 elite divisions were preparing to resist the Soviet Red Army's advance after the Battle of Târgul Frumos.