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What datums were used in North America before NAD27? I googled around on this without luck.

Also I found an old nautical chart of Lake Michigan, dated 1876, which states:

Longitudes on this map depend on that of Fort Howard astronomical station adopted in 1874 as 88 00' 57.82". Latitudes are derived geodetically from Fort Howard.

Don't know what that means.

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  1. New England Datum of 1879

    Was the first geodetic datum of this type in the United States. The reference ellipsoid was Clarke Ellipsoid of 1866.

  2. United States Standard Datum of 1901 (First North American Datum)

    In 1901 the United States Coast and Geodetic Survey adopted a national horizontal datum called the United States Standard Datum, based on the Clarke Ellipsoid of 1866. It was fitted to data previously collected for regional datums, which by that time had begun to overlap. In 1913, Canada and Mexico adopted that datum, so it was also renamed the North American Datum.

P.S. Indigenous North Americans and history geeks, please check me up.

References:

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