Hanging Rock

Historical marker location:

Lagro, Indiana

( Marker can be reached from E. Hanging Rock Road, 0.8 miles east of State Road 524, on the left when traveling east.)

National Natural Landmark.

The first public demonstration of the electric light bulb was given by Thomas Edison in Menlo Park, New Jersey, but the first practical incandescent light bulb was invented by Lewis Howard Latimer, who was born in Chelsea, Massachusetts, but lived in Indiana for a time. Latimer was also the first African American to be employed as an engineer by the U.S. Patent Office.