Second Principal Meridian

The Second Principal Meridian coincides with 86° 28' of longitude west from Greenwich, starts from a point two and one half miles west of the confluence of the Little Blue and Ohio rivers, runs north to the northern boundary of Indiana, and, with the base line in latitude 38° 28' 20", governs the surveys in Indiana and part of those in Illinois.

Source

• Raymond, William Galt (1914) (via Google Books). Plane Surveying for Use in the Classroom and Field. New York: American Book Company. http://books.google.com/books?id=68I3AAAAMAAJ&dq. 
• "Chapter Five: Land Surveying". Survey Manual. Springfield, Illinois: Illinois Department of Transportation, Bureau of Design and Environment. 2003-02-28. p. 5–5. http://www.dot.state.il.us/desenv/survey/chap5.pdf. Retrieved 2008-10-30.