- The name is of German origin, spelled Brumbach, and is found in both German and Swiss records with "u" and "o." "Brum" is apparently a contraction of "Brummen," meaning noisy or roaring, something humming. "Bach," a brook. The name in the first instance described an ancestor by locality, a common old method of designation. Thus, the German spelling of Brumbach suggests they came from an area with a roaring brook.
- In America, names ending in "bach" usually became "baugh."Whether written with the more prevalent "u" or "o" it was pronounced with the long German "oo" as in moon, or more rarely with the short "u" sound in good.
- Records researched identify Brumbach families in Switzerland, Germany, and France. The Thirty Years' War waged in the German states from 1618-1648 destroyed many records, as well as causing a general dispersion of the various branches of the families.
- The Brumbach families seemed to locate in two separate areas - in the Wiesental River valley, which flows into the Rhine near Basel, Switzerland, and in Westphalia, about fifty miles east of Cologne, Germany. It seems to be definitely established that an extensive family settled in an ancient settlement in the Wiesental valley called "Brombach," from which they took their name. Brombach families can be found in Basel, Rheinfelden, Beuggen, Brombach, Minseln, Nordschwaben, Karsan and the surrounding area on both side of the Rhine River.
- Those families remaining at Minseln, Nodschwaben and Karsan remained Catholic in the Reformation period, while those at Rheinfelden became Protestants - under different governments. The inhabitants of Rheinfelden early left the Catholic religion, became Protestants, and later Altkatholiken (old Catholic, or reformers), which they remain. These inhabitants suffered greatly and were bitterly persecuted, causing most of the inhabitants to emigrate during the eighteenth century - the Brombachs-Brumbachs then emigrated.
- The second area where the Brumbach families seemed to originate was in Westphalia, near the town of Muesen, a few mile north of Siegen and about fifty miles east of Cologne, Germany.
- At the early date of 1582 universal compulsory education was established in Nassau-Siegen. Because of the varied economy, relatively little war damage, and education the inhabitants enjoyed a moderate amount of prosperity. By the time of the first migration to America this area was one of the most progressive and prosperous in Germany.
- Dr. Gaius Brumbaugh wrote, "A careful study of the reproduced immigrants lists, or ship papers, will show that the Brumbaugh-Brombach immigrants, whose signatures have been preserved, wrote good German scrip, even paying attention to the umlaut, or distinction for u."
From the immigrant Johannes Henrich Brumbaugh down through the generations a large number of descendants were members of the German Baptist Brethren Church.