ORONO – Earle G. Shettleworth Jr. will speak on Orono’s “Historic Buildings and Places” during a free bicentennial lecture 7 p.m. Thursday, May 18, in the Orono Municipal Building, 59 Main St.

Prior to the lecture, at 6:15 p.m., the public is invited to assemble near the obelisk honoring Chief Joseph Orono to tour the former St. Mary’s School, which has been converted to Mainview, a private residential complex.

Shettleworth, who is state historian, has had a decades-long career studying the architectural heritage of Maine towns and cities.

A native of Portland, he was just 13 when his interest was sparked by the destruction of Portland’s Union Station in 1961.

In the 1960s, he was an active member of Greater Portland Landmarks. In 1971 he was appointed by Gov. Kenneth Curtis to serve on the first board of the Maine Historic Preservation Committee.

He became architectural historian in 1973 and director in 1976. Shettleworth has lectured and written extensively on Maine history and architecture. His most recent publication was “John Calvin Stevens on the Portland Peninsula.”

He is chairman of the Capitol Planning Commission, the Blaine House Commission and the Capitol Park Commission. Gov. John Baldacci appointed him state historian in 2004.