After his father died, Patterson took over the management of the "Tribune". He had a dispute about how to run the "Tribune" with his cousin, Robert R. McCormick. After World War I ended, he visited London and observed a newspaper in tabloid form for the first time. Patterson moved to New York City and founded the "New York Daily News" as a tabloid on June 26, 1919, with McCormick as co-editor and publisher. However, the two were unable to resolve their dispute, so in 1925 Patterson ceded full authority over the "Tribune" to McCormick in return for full control of the "Daily News."