In 1885, Lalor taught at East Side High School, Milwaukee.
[2] Lalor worked as a translator in the Director of Mint, U. S. Treasury Department.
[3] Lalor collaborated with Louis Wolowski, Ludwig Nohl, and Paul Shorey.
He translated works by Rudolf von Jhering and Wilhelm Roscher.
He translated from German two works by Ludwig Nohl, a biography of Ludwig Beethoven in Life of Beethoven (1881)[4] and Wolfgang Mozart in Life of Mozart (1880).