The Hotcąk or Winnebago alphabet was adapted from the Fox syllabary, which was invented in the 1870s.
Used to write: Hotcąk (Winnebago, Hocak Wazijaci, Hochank, Hochunk), a Siouan language with about 230 speakers in the US states of Wisconsin, Illinois and Nebraska. The Hotcąk speakers call themselves Hotcągara. Speakers of this language in Nebraska call themselves Winnebago and are recognised as a separate tribe.
source
wikipedia.org,
omniglot.com &
ethnologue.com