Conn's first factory was destroyed by fire 29 January 1883 (his thirty-ninth birthday), and he erected a new building on the same site.
In 1886 rumors began to circulate that Conn wanted to move his business to Massachusetts.
Its early business was based primarily on brass instruments, which were manufactured in Elkhart, Indiana.
During the 1950s the bulk of its sales revenue shifted to electric organs.
The business also distributed American-made and imported guitars, banjos and zithers.
Conn's company was a source of competitors as well as instruments.
Conn then announced his intentions to build a third factory on the corner of East Beardsley and Conn Avenues.Conn was induced to stay after the public raised a large sum of money by popular subscription and gave it to him.In 1887 Conn purchased Isaac Fiske's brass instrument manufactory (upon Fiske's retirement) in Worcester, Massachusetts.The company was sold in 1980 then again in 1985, reorganized under the parent corporation United Musical Instruments (UMI) in 1986. Conn survives as a brand of musical instruments manufactured by Conn-Selmer. With the outbreak of the American Civil War he enlisted in the army on at the age of seventeen, despite his parents' protests.The assets of UMI were bought by Steinway Musical Instruments in 2000 and in January 2003 were merged with other Steinway properties into a subsidiary called Conn-Selmer. On 14 June 1861 he became a private in Company B, 15th Regiment Indiana Infantry, and shortly afterwards was assigned to a regimental band.