The Muhlenberg legend is an urban legend in the United States and Germany. According to the legend, the single vote of Frederick Muhlenberg, the first ever Speaker of the U.S. House of Representatives, prevented German from becoming an official language of the United States.
Basis of legend
The kernel of truth behind this legend is a vote in the United States House of Representatives in 1794, after a group of German immigrants asked for the translation of some laws into German. This petition was rejected by a 42 to 41 vote and Muhlenberg (of German descent himself, who had abstained from that particular vote) was later quoted as having said "the faster the Germans become Americans, the better it will be."
The United States has no statutory official language; English has been used on a de facto basis, owing to its status as the country's predominant language. At times various states have passed their own official language laws.
The legend has a long history, and led to a number of analyses and articles published from the late 1920s into the early 1950s explaining why the story was not true. The story was dubbed the "Muhlenberg legend" by at least the late 1940s. Nevertheless, the legend persists.
For example, in 1987, a letter from a former election official in Missouri emphasized the importance of voting in an Ann Landers column. He included a list of events allegedly decided by one vote from his local election manual, including that “in 1776, one vote gave America the English language instead of German." (In fact, versions of this error-filled list long predate the 1987 Ann Landers mention.) This led to another round of news stories again pointing out that this was a myth. Oblivious to corrections of this sort, Ann Landers ran the same list again in November 1996. A chorus of dismayed responses caused Landers to clear up the matter in a subsequent column. According to one letter writer, who begged Landers to "stomp out that piece of fiction wherever you encounter it," the myth gained traction in the 1930s due to the work of Nazi propagandists. 
Another version of the myth puts the vote in 1774 by the Continental Congress, which appeared in Ripley's Believe It or Not! as early as 1930. Ripley's included the myth in a 1982 book as well. Ripley's version credits the story to an alleged letter by Heinrich Melchior Muhlenberg published in Halle in 1887.
Most accounts credit Franz von Löher as the source of the legend. Löher was a German visitor to America who published the book Geschichte und Zustände der Deutschen in Amerika (History and Achievements of the Germans in America) in 1847. Löher seemingly placed the crucial vote only in Pennsylvania, to make German the official language of that state, not the United States as a whole. (Philadelphia was where the U.S. Congress sat at the time, but it was also the capital of Pennsylvania. To further confuse matters, Muhlenburg did serve as Speaker of the Pennsylvania House before serving in that title for the U.S. Congress.) According to Löher, the vote was tied, and Muhlenberg cast the tie-breaking vote for English.
- Heath, Shirley Brice & Frederick Mandabach. Language Status Decisions and the Law in the United States, in Cobarrubias, Juan & Joshua A. Fishman, eds., Progress in Language Planning, p. 94 (1983)
- Sick, Bastian (19 May 2004). German as the official language of the USA?, Spiegel Online (in English)
- The German Vote, Snopes.com, July 9, 2007
- (18 February 1943). A German Language Rumor Traced Down, by W.L. Werner in American Speech magazine, reprinted in The Milwaukee Journal
- Feer, Robert A. Official Use of the German Language in Pennsylvania, The Pennsylvania Magazine of History and Biography (Vol. 76, No. 4) (October 1952)
- Arndt, Karl J. R. German as the Official Language of the United States of America?, Monatshefte, Vol. 68, No. 2 (Summer, 1976), pp. 129–150 (Arndt's article attempts to trace pre-Loher accounts which may have helped foster the legend, including an 1813 article by Justus Christian Henry Helmuth; at n. 21, Arndt lists seven accounts published between 1927–52 debunking the myth, starting with the 2nd edition of Albert Bernhardt Faust's The German Element in the United States, at Vol. II, pp. 652–56 (1927))
- Lohr, Otto. Deutsch als 'Landessprache' der Vereinigten Staaten?, Mitteilungen der Akademie zur wissenschaftlichen Erforschung und zur Pflege des Deutschtums 4 (1931): 283–90 (in German)
- Wood, Ralph C. The Second Period of the German Society of Pennsylvania and the Muhlenberg Legend, publication?, cited in The German American Review, 1949
- (8 August 1981). Zepezauer, Frank S. When German almost became our language, Milwaukee Journal
- Baron, Dennis (March 1996). watzmann.net: Urban Legend: German almost became the official language of the US, watzmann.net (reprinting 1996 essay by Dennis Baron, full account of the legend and its origin)
- Adams, Willi Paul et al. Indiana University-Purdue: German or English?, in The German-Americans: An Ethnic Experience (1993)
- (19 March 1968). Single Votes Have Made History, Sumter Daily Item
- Baron, Dennis. The Legendary English-Only Vote of 1795, pbs.org
- (7 April 1987). Importance of one vote overlooked by Americans, Kentucky New Era (syndicated Ann Landers column)
- (4 November 1996). Debate continues on Internet pros and cons, Ocala Star-Banner
- (30 December 1996). Here's A Good Book That Will Grab You, Chicago Tribune
- Zagofsky, Al (5 February 2011). Was German almost the official language of the U.S.?, Times-News
- Believe It or Not: A Refutation of Mr. Ripley's Very Absurd Fabrication Concerning the Continental Congress, Carnegie Magazine (1930)
- Ripley's believe it or not! book of chance (1982)
- Loher, Franz. Geschichte und Zustände der Deutschen in Amerika (1847) (in German) via archive.org
- Mencken, Henry L. The American Language: Supplement One, pp. 138–39 (1945)
- Von Löher, Franz. Geschichte und Zustände der Deutschen in Amerika (1847) (in German) via archive.org