The First Silurian carbonate buildup in North America to be correctly identified as a reef was in eastern Wisconsin, in 1862. In the ensuing 125 years, many hundreds of studies were presented on other Silurian reefs in the Michigan Basin and environs. Successive trends in both scientific and economic interests have characterized the quest to learn what riches these reefs may yield. Three periods are recognizable: (1) An early period of discovery, extending until 1926, saw more incorrect ideas to explain the once-mysterious reefs than correct ideas, e.g., ideas of volcanism and upheavals. James Hall, who advanced both incorrect and correct ideas, best typified this period, but T. C. Chamberlin should be credited most for his lasting insight. (2) A middle period of enlightenment, 1927 to 1960, saw a convincing reef proof and a systematic set of biologic reef parameters set forth by (especially) E. R. Cumings, R. R. Shrock, and H. A. Lowenstam. (3) A modern period of integration, 1961 to present, could have been designated as one of proliferation, so numerous were the new reef models and ideas concerning reef geometry, distribution, diagenesis, evaporite relations, deep- versus shallow-water environments, basin-to-shelf differences, cyclicity in deposition, sea-level changes, tectonism, and hydrocarbon accumulation. Many of these ideas conflict; thus, I choose the regionally broad stratigraphic integration that developed as the most significant key to the modern period and the several debates that yet require reckoning against the modern stratigraphic framework. The stratigraphic relations favored in this chapter depart from tradition, but they suggest several kinds of studies that need to be undertaken.