He began to practice architecture the following year while continuing to teach. A former student of his, Lew Porter, came into the firm as a partner. Conover & Porter designed government buildings, banks, churches, residences and other commercial buildings, many of which still stand and many are on historical registries.
Before the firm dissolved in 1899, a number of young architects worked for Conover & Porter, including a very young Frank Lloyd Wright.
Conover & Porter were based in Madison, but also had offices in Ashland and Baraboo.