SPRINGFIELD, Ill. — About 175 years after the U.S. government stole land from the chief of the Prairie Band Potawatomi Nation while he was away, Illinois may soon return it to the tribe.

Nothing ever changed the 1829 treaty that Chief Shab-eh-nay signed with the U.S. government to preserve for him a reservation in northern Illinois: not subsequent accords nor the 1830 Indian Removal Act, which forced all indigenous people west of the Mississippi. But around 1848, the U.S. sold the land to white settlers while Shab-eh-nay and others of his tribe visited family in Kansas.

To right the wrong, Illinois would transfer a 1,500-acre state park 68 miles west of Chicago that was named for Shab-eh-nay, to the Prairie Band Potawatomi Nation. The state would keep up the maintenance, and the tribe wants the park to stay as it is.

“The average citizen shouldn’t know that title has been transferred to the nation so they can still enjoy everything that’s going on within the park and take advantage of all of that area out there,” said Joseph “Zeke” Rupnick, chairman of the Prairie Band Potawatomi Nation based in Mayetta, Kansas.

It’s not entirely the same soil that the U.S. took from Chief Shab-eh-nay. The boundaries of his original 1,280-acre reservation now encompass hundreds of acres of privately owned land, a golf course and county forest preserve. The legislation awaiting Illinois House approval would transfer the Shabbona Lake State Recreation Area.

No one disputes that Shab-eh-nay’s reservation was illegally sold and still belongs to the Potawatomi. An exactingly researched July 2000 memo from the Interior Department found the claim valid and shot down rebuttals from Illinois officials at the time: “It appears that Illinois officials are struggling with the concept of having an Indian reservation in the state.”

In 2006, the tribe purchased 128 acres in a corner of the original reservation and leases it for farming. The U.S. government in April certified that as the first reservation in Illinois.

Now, proponents will seek endorsement of the park measure when the Legislature returns in November for its fall meeting.