Willis's official papers were donated to and are open for research at the Ohio Historical Society.

The site is maintained by the Ohio Historical Society.

It is now operated by the Ohio Historical Society.

Another vessel fragment is on display at the Ohio Historical Center.

The house is owned by the Ohio Historical Society.

He was president of the Ohio Historical Society from 1907 until shortly before he died.

The site is preserved as a state park by the Ohio Historical Society.

It ceased operations in 1976, and turned its archives over to the Ohio Historical Society.

The journal was established in 1887 and published by the Ohio Historical Society.

The museum is operated by the Ohio Historical Society.