100th Meridian Oklahoma/Texas State Line

100th Meridian Oklahoma/Texas State Line is an Oklahoma historical marker in Harmon County.

Harmon County · on US-62, four miles west of Hollis

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The Adams-Onís Treaty (1819) designated the 100th Meridian as the boundary between the United States and New Spain (Spanish Mexico). The location of the 100th Meridian remained under dispute after the admission of Texas into the Union in 1845. In 1927, the US Supreme Court confirmed the 100th Meridian as the Oklahoma-Texas border and assigned engineer Samuel S. Gannett to locate and mark the state line.

TodayHistorical map

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David Rumsey Map Collection, Stanford Libraries

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Marker data: Oklahoma Historical Society, Historical Marker Program. Marker texts come from the Society's marker database, reproduced with the Society's written permission. Where the database describes a marker's location in words but records no coordinate, the pin on this page is ours, worked out from that description and marked approximate.
Sponsored by 100th Meridian Chapter Daughters of the American Revolution
This marker on the program's own site

100th Meridian Oklahoma/Texas State Line

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