Robert Briggs patented the first cast iron steam radiator in 1862. Prior to this, Franz San Galli developed a device called a hot box in 1855 that many consider to be the first hot water radiator.
In 1872, Nelson Bundy created the Bundy Loop, a series of elongated cast iron loops attached to a cast iron base that resembles the classic style familiar to most people today.
The history of steam heating dates back to ancient times, when Romans ran hot water through pipes beneath floors to heat buildings. Jean Simon Bonnemain developed the first enclosed hot water system in Paris in 1777 for incubating chicken eggs. The Marquis de Chabbanes developed a system for heating large areas in 1817 as a method for keeping the grape vines of his wealthy clients warm.
Angier Perkins developed a boiler and expansion tube known as a steam heater in 1841. His assistant, Joseph Nason, improved upon the idea and moved to New York, where he formed the American Radiator Company the following year. Together with Robert Briggs, they designed and produced a radiator using vertical wrought iron tubes that Briggs patented in 1862.