Cycle racing on purpose-designed tracks dates back to the 1860s, when "path" races were held on shale running tracks. By the end of the century, following the introduction of the safety bicycle it had become a major spectator attraction in many countries, and banked concrete and asphalt tracks, often around the outside of running tracks or other sports grounds, were built in profusion. Timber indoor tracks, permanent or temporary, were also built for the increasingly popular six-day races. The outdoor racing was heterogenous in style, with various short sprint-type events, often handicapped by distance, and longer "stayer's" events where riders were paced by tandems, triplets, quadruplets, and even more extravagant multi-rider machines, later to be supplanted by motorcycles. Track cycling was an Olympic discipline from the first modern games in 1896, where medals were awarded for the match sprint and 5 km, 100 km (paced) and 12 hour races; World Champinships of the same era were run at distances of one mile and 100 km for amateurs and professionals.
Towards the middle of the 20th century the patterns of racing settled down into the majority of the disciplines still raced today: match sprints, pursuiting, points races, and motor-paced races at outdoor meetings in the summer, plus the six-day circuit in the winter. In the days before television took over entertainment, meetings large and small could still turn a profit from paying spectators, and although there was a strict pro-am divide, the rules were circumvented in various ways, often by the provision of large prizes in kind which were promptly sold back to the supplier at cost. Outdoor racing was still largely on shallow cement bowls around the outside of a 440m/440 yard running track; where the facilities didn't exist, an ad hoc oval could even be marked out on a playing field for grass track events at a local fete.
From the 1960s onwards, the tracks' fortunes took a downward turn as spectator numbers slumped; throughout cycling's heartland television coverage boosted the already considerable popularity of road racing at the expense of the summer track, while the six-day season dwindled away to a handful of events, mainly in Germany. The Olympic disciplines were dominated by riders from the Soviet Union and East Germany, while the professional scene dwindled away to an extremely small circus - so much so that in 1974 Reg Harris, a star sprinter of the 1940s and early 1950s, was able to make a professional comeback in his 50s to win the British national championship.
With the collapse of the Eastern bloc, the rigid pro-am distinction was eroded over the next couple of decades; 1992 saw the last segregated world championships, and the UCI shook up the championship disciplines, dumping the motor-paced event and tandem sprinting and introducing the men's Keirin and "Olympic sprint" and (long overdue) more women's events. The focus of serious track racing was henceforth to be exclusively on board tracks of 200, 250 or 333 m, under cover to prevent rain from disrupting TV schedules. There are some 800 velodromes around the world and, although they are rarely moneyspinners these days, more are still being built.
Metanode-ish stuff follows:
Disciplines and events