Old Market House (Galena, Illinois) Old Market House (Galena, Illinois) The Old Market House, currently being operated as the Galena Welcome Center, is a brick building built in the Greek Revival style in 1845 in Galena, Illinois. It is owned and operated by the Illinois Historic Preservation Agency as an Illinois State Historic Site. The Old Market House was built by the city of Galena to serve as a city hall and enclosed public farmer's market. A rapid increase in population in the Galena area in the 1830s and 1840s, largely a result of the discovery of galena, a kind of lead ore found in
Galena applied to pottery. Galena is a semiconductor with a small band gap of about 0.4 eV, which found use in early wireless communication systems. It was used as the crystal in crystal radio receivers, in which it was used as a point-contact diode capable of rectifying alternating current to detect the radio signals. The galena crystal was used with a sharp wire, known as a "cat's whisker" in contact with it. The operation of the radio required that the point of contact on the galena be shifted about to find a part of the crystal that acted as a rectifying