One of Tivnan's major decisions as president was regarding the university's medical school, an institution that had struggled to stay afloat since its opening some years earlier; lack of funds and low enrollment meant that unless sufficient funding could be found immediately, the school would have to be closed.

[8] Another noteworthy achievement was the enrollment of the first Black woman in the Fordham School of Law, Ruth Whitehead Whaley, in 1921.

In 1910, previous to Tivnan's appointment as president, he was serving as a chemistry instructor at the university when he installed a seismograph in the basement of an administrative building on the Bronx campus.

[10] Today the facility is the oldest seismography station in New York City,[11] and is part of the National Seismic Network, reporting to the United States Geological Survey in Boulder, Colorado.

[12] The seismography station was officially dedicated and opened in 1924, shortly after Tivnan left Fordham University.