Muhlenberg Brothers was one of the dominant architecture/engineering firms in Reading, Pennsylvania during the first half of the 20th century.
It was established in 1892 by Charles Henry Muhlenberg IV (1870–1960), who graduated from the Massachusetts Institute of Technology and apprenticed under the architect Frank Furness. His brother, Frederick Hunter Muhlenberg II (1865–1933), attended both Lafayette College and MIT. The founder's son, Charles Henry Muhlenberg V (1899–1985), attended the University of Wisconsin and MIT, and joined the firm in 1923. Frederick Hunter Muhlenberg II left the firm in the mid 1920s to go into partnership with his nephew, Frederick Augustus Muhlenberg II, operating as Muhlenberg & Muhlenberg.
Muhlenberg Brothers designed both residential and commercial works, and large projects such as office buildings, churches and factories. Among the commissions were a vaudeville theater, a number of public school buildings, and much of the campus of Albright College. G. Russell Steininger, landscape architect, was a principal in the firm by 1929. Its main offices were located at 113-A South Fourth Street in Reading. It established a branch office in Pottsville, Pennsylvania, and one in St. Petersburg, Florida in the 1920s. By 1937, Frederick H. Muhlenberg II had died, Charles H. Muhlenberg IV was listed as a consultant, G. Russell Steininger was no longer part of the firm, and Charles H. Muhlenberg V and Frederick R. Shenk were the principals. The firm continued until about 1965, when Shenk formed Frederick R. Shenk & Lee V. Seibert.
The Historical Society of Berks County owns two portfolios of photographs of Muhlenberg Brothers buildings, from 1929 and 1937, along with hundreds of blueprints from the firm.
A number of the firm's works are listed on the U.S. National Register of Historic Places.