Rubuta ci gaba don wannan sakin layi - Vélez Sarsfield ya haɗu da kansa tare da Janar Bartolomé Mitre, mai ba da shawara mai mahimmanci na Buenos Aires, bayan da aka rushe Rosas
, kuma yayi aiki a matsayin mai ba da shawara ga Mitre a cikin adawa da Yarjejeniyar San Nicolás ta 1852 (wanda Buenos Aires ya ƙi). Bayan rabuwa da lardin, Vélez Sarsfield ya tsara Tsarin Mulkin Jihar Buenos Aires na 1854 ga Gwamna Pastor Obligado. Rashin nasarar lardin a yakin Cepeda ya haifar da sake haɗuwa da Argentina, wanda Vélez Sarsfield ya taimaka wajen tsara jerin gyare-gyaren da ake buƙata ga Kundin Tsarin Mulki na Argentina.