This paper evaluates a largely overlooked thesis developed by Juan Bautista Alberdi of Argentina’s 19th-century economic development using econometric time-series methods. Annual series of GDP per capita, export performance, and monthly London prices of bonds issued by the Republic of Argentina and the Province of Buenos Aires are used to test whether major institutional events in 1853, 1862, and 1880 correspond to statistically significant structural changes in economic performance and sovereign credit risk. The results provide consistent evidence of institutional turning points consistent with Alberdi’s thesis and challenge conventional interpretations that identify the early 1860s as the start of Argentina’s convergence to the Western Offshoots.