In the 1870s, La Farge began to paint murals, which became popular for public buildings as well as churches. His first mural was painted in Trinity Church, Boston, in 1873. Then followed his decorations in the Church of the Ascension (the large altarpiece) and St. Paul's Chapel, New York. He also took private commission from wealthy patrons (e.g. Cornelius Vanderbilt) and was reputedly worth $150,000 at one point. La Farge continued to create murals through his career: for the Minnesota State Capitol at St. Paul, at age 71, he executed four great lunettes representing the history of law. He created a similar series based on the theme of Justice for the State Supreme Court building at Baltimore, Maryland.