Initially, Wisconsin's Supreme Court was just composed of the five judges of the five state judicial circuits.
[4] In 1853, a separate Wisconsin Supreme Court was created with all members elected state-wide.
Initially the court was three members; it grew to five justices in 1878, and to its current size of seven seats in 1907.
Initially, the chief justice and associate justices were separate offices elected by the public, but a constitutional amendment ratified in 1889 converted all members of the court to "justices" and deemed that the "chief justice" would always be the justice who had served longest on the court (seniority).
126 years later, another constitutional amendment changed the selection rules for chief justice, abolishing the "seniority" rule, and instead mandating that the justices of the court would elect a chief justice from their members every two years.