A rare letter by Ludwig van Beethoven is among more than 400 historical documents coming to auction.
The Profiles in History sale is June 13, online and at its Calabasas, California, galleries.
In his 1806 letter, Beethoven writes a conciliatory request to court theatre director Baron Peter von Braun.
They had argued over royalties for his only opera "Fidelio".
It's expected to bring $US150,000 ($A162,294) to $US250,000.
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Other highlights include a speech by Muhammad Ali written for a college lecture tour in the 1960s.
Handwritten on index cards, it presents Ali's views on the Muslim faith and race relations. At the time, Ali was barred from boxing for refusing to be inducted into the armed forces.
The speech could bring up to $US12,000.
Other highlights include documents by Nikita Khrushchev and Al Capone.
