William Frishmuth (April 22, 1830–August 1, 1893) was a German-born American architect and metallurgist.
William Frishmuth was born Johann Wilhelm Gottfried Frischmuth in Coburg, Germany in 1830. Aluminum is a metal not found in a pure state in nature. The first patent for refining aluminum by electrolysis was granted to Friedrich Wöhler of Germany. Frishmuth studied with Wöhler in Germany before coming to America.
In 1861 Frishmuth became a special secret agent to the War Department at the request of Abraham Lincoln. On 5 November 1861, he received authority from President Lincoln, which was confirmed by Governor Curtin of Pennsylvania, to raise a cavalry regiment. In 1862 the regiment was raised for active service, and was commissioned a colonel. He was colonel of the 113th Regiment, Twelfth Pennsylvania Cavalry (Curtin Hussars) until April 20, 1862.
In 1876 he produced the first authenticated aluminum castings made in America at his Philadelphia foundry (now an historic landmark) He used a chemical process, unlike the electrolytic processes used today. One of the first castings he produced was an engineer's transit. The foundry was declared an ASM (American Society for Materials) Historical Landmark in 1985.
Because Frishmuth had previously done plating work for the Washington Monument the Army Corps of Engineers asked Frishmuth to construct a small metal form for the top of the monument. The small pyramid was to be artistic, and function as the terminus of a lightning rod. Frishmuth suggested aluminum, as its color would blend well with the granite, would not stain, would polish well, and be engraved with inscriptions.
In 1884 he cast the aluminum cap, which was the first architectural use of aluminum. At that time aluminum was $1.00 per avoirdupois ounce. For perspective, silver was $1.30 per troy ounce ($1.18 per avoirdupois ounce); 100 ounces (about 2.8 kg) of aluminum were needed to produce the pyramid.
Through his lifetime, Frishmuth received 12 patents, mostly on electroplating and production of aluminum.
Annually, the (AFS) American Foundry Society presents the "Frishmuth Award" honoring the "Foundryman of the Year".