Following the struggle for independence, the progressive new Governor of Buenos Aires, Martín Rodríguez, assigned Pergamino a Justice of the Peace in 1822 and the first school was opened in 1828. The town soon became home to a number of abattoirs and following the 1829 rise of Governor Juan Manuel de Rosas (whose family interests centered around cattle-raising) a close alliance developed between the governor and Pergamino's most prominent families, the Acevedos and the Anchorenas; Rosas' repressive regime, however, resulted in the sole school's closure in 1838. Following Governor Rosas' 1852 overthrow, the local gentry allied themselves to Bartolomé Mitre, a prominent advocate on behalf of Buenos Aires Province for greater autonomy. Mitre was elected governor in 1860 and President of Argentina in 1862. President Mitre's 1862 establishment of Argentina's first institute of Agronomy helped lead to the development of a new economic activity in the region around Pergamino: intensive agriculture. The first Argentine grain shipment to arrive intact in the United Kingdom in 1875 touched off an agricultural boom that for Pergamino, resulted in the massive cultivation of maïze. The city's growth accelerated further upon the arrival of the Central Argentine Railway in 1882, en route to Rosario. Pergamino, whose population by then exceeded 10,000 and home to over 90 registered businesses, was formally designated as a city on 23 October 1895.