There are Tecumseh High Schools in Indiana, Michigan, Ohio and Oklahoma, and MaxPreps offers the football results for the Tecumseh schools in all four states as of 2015. Local newspapers and some national websites also provide scores as well as statistics.
The website MLive.com, which publishes news from eight newspapers, has game results for Tecumseh High School in Michigan dating back to 2007. The Dayton Daily News reports scores on Tecumseh High School in Ohio.
The NFHS Live website, operated by the National Federation of State High School Associations, has the Ohio high school's results. Score Stream has football results for all four schools; type "Tecumseh" in the search box, and then select a school.