Brick. At New Ulm, Wm. Winkelmann owns the only brick yard. (The Geological and Natural History Survey of Minnesota, First Annual Report For The Year 1872, N. H. Winchell, Press Printing Company, St. Paul, 1873, Page 209)
The same kind of greenish marl is exposed up to the Waraju, the immediate bluffs being somewhat wrought in it, to a point just back of New Ulm, where the bank is opened by Mr. Winkelmann for laying pipes to supply his machinery and brick-yard. The trench which he has dug passes through it just before reaching the bank of the Waraju river. (The Geological and Natural History Survey of Minnesota, The Second Annual Report, For The Year 1873, N. H. Winchell, St. Paul Press Company, St. Paul, 1874, Page 184)
Bricks. The brick-yard at New Ulm, situated close southeast of the city, on a terrace about 40 feet above the river, formerly owned by William Winkelmann, was purchased in 1879 by Fritz Aufderheide, who made about 1,000,000 bricks here in 1880, selling them at $6.50 per thousand. (The Geological and Natural History Survey of Minnesota, 1872-1882, Volume I, N. H. Winchell & Warren Upham, Johnson, Smith & Harrison, Minneapolis, 1884, Page 587)
Fire-bricks. From Cretaceous beds on the Cottonwood river, good fire-bricks have been made by Christian Dauffenbach, by William Winkelmann, and by John Stoeckert, at New Ulm. The characters of the deposits used, and in what proportion, have been stated already in the description of the section in which they occur (page 574). (The Geological and Natural History Survey of Minnesota, 1872-1882, Volume I, N. H. Winchell & Warren Upham, Johnson, Smith & Harrison, Minneapolis, 1884, Page 588)