It is located between the Mount Lofty Ranges on the west and the Murray River further to the east.

The Hundred of Bagot is almost exactly spans the boundaries of the contemporary town of Sedan.

The Hundred of Bagot was proclaimed in 1860 by Governor Richard Graves MacDonnell.

In 1918 many South Australian place "names of enemy origin" were changed to sound less German and the North Rhine council, like the hundred it governed, had its name changed.

In September 1933 the District Council of Swan Reach amalgamated with Keyneton to become new District Council of Keyneton and Swan Reach, bringing the hundred under local administration of that body.