In June 1821, he was named minister of government to Buenos Aires by governor Martín Rodríguez. Over the next five years, he exerted a strong influence, and focused heavily on improving the city of Buenos Aires, often at the expense of greater Argentina. To make the former look more European, Rivadavia constructed large avenues, schools, paved and lighted streets. He founded the University of Buenos Aires, as well as the Theatre, Geology, and Medicine Academies and the continent's first museum of natural science.