The Celtic Revival was an international movement. The Irish-American designer Thomas Augustus "Gus" O'Shaughnessy made a conscious choice to use Irish design roots in his artwork. Trained in stained glass and working in an Art Nouveau style, O'Shaughnessy designed a series of windows and interior stencils for Old Saint Patrick's Church in Chicago, a 10-year project begun in 1912. Louis Sullivan, the Chicago architect, incorporated dense Art Nouveau and Celtic-inspired interlace in the ornament of his buildings. Sullivan's father was a traditional Irish musician and they both were step-dancers. In England, the Watts Mortuary Chapel (1896–98) in Surrey was a thoroughgoing attempt to decorate a Romanesque Revival chapel framework with lavish Celtic reliefs designed by Mary Fraser Tytler.