Yes, base ball. That is the way newspapers and Badger yearbooks spelled (or is that “spelt”?) the word in the early days.

Baseball was the first intercollegiate sport at the University of Wisconsin.  In 1870, a group of students who wanted to play baseball and earn their degrees at the state’s flagship university got approval to start a baseball team called the Mendotas, likely from the name of one of the four lakes surrounding Madison and the one closest to campus.  The team played its first game on April 30, 1870 and beat a local club called the Capitol City Nine, 54-18.  The Mendotas won three of their next four games for a 4-1 inaugural record.  The season final against the Janesville Mutuals was a wild and woolly 41-40 contest in favor of the Mendotas with the following lineup as written in a 1911 article for Wisconsin Alumni Magazine by George Noyes:

George H. Noyes, Wisconsin’s first second baseman.