In 1886, he became a street-sweeper with Chicago’s
West Park District. While living here, at 1141 North
Sacramento Boulevard, he rose to become
Superintendent of Union and then Humboldt Park.
Jensen redesigned Humboldt, Douglas and Garfield
parks using indigenous species in natural
settings, but he felt his greatest masterpiece was
Columbus Park, designed in 1916.

Jensen was inspired by nature, and created the Prairie Style of landscape
design. Straight lines had no place in his work, he said, because “landscaping
must follow the lines of the tree with its thousands of curves.”

Jensen championed the network of forest preserves around Chicago, the
protection of the Indiana Dunes and Illinois’ state park system. He designed
many private estates throughout the Midwest, as well as the Lincoln Memorial
Garden in Springfield, Illinois. In 1935, Jensen left Chicago to found The
Clearing, a rustic school and retreat in Wisconsin, where he remained until his
death.