In the early 1800s, the village was a center for the mining of iron ore, furnishing employment to many men. Around 1855, the Allentown Railroad was graded through Breinigsville, but the tracks were never laid. In the 1860s, the Catasauqua and Fogelsville Railroad used the grade to build from Trexlertown, on its main line, into Breinigsville, as part of a branch to serve local limonite (iron ore) mines. The largest deposit of pyrite ore in the region was located northwest of Breinigsville. Later, the village was served by the Allentown-Reading Traction Company. These mines had shut down by the end of World War I, and the rails through Breinigsville were consequently abandoned. They were finally removed in the 1940s.