Marion County was
created by the Provisional Legislature of
Oregon on July 5, 1843 as the Champooick
District, one of the original
four districts of the Oregon Country along
with Twality (later Washington),
Clackamas, and Yamhill counties.
The four districts were redesignated
as counties in 1845.
Originally, this political entity
stretched southward to the California
border and eastward to the Rocky
Mountains. With the creation
of Wasco, Linn, Polk, and other counties,
its area was reduced in size. Marion
County's present geographical
boundaries were established in 1856.
In 1849, Salem was designated the
county seat. The territorial capital was
moved from Oregon City to
Salem in 1852. The ensuing
controversy over the location of the
capital was settled in 1864 when Salem
was confirmed as the state capital.