Editing Mandan, North Dakota (section)

===Early history===
While Native Americans had long established settlements in the area along the river, the first white explorer was Frenchman Sieure de la Verendyre, whose expedition arrived in 1738. Not until the early 1800s did Euro-American frontiersmen come to the area with any regularity, the [[Lewis and Clark Expedition]] in 1804 and 1806, [[George Catlin]] in 1832, and [[Prince Maximilian of Wied-Neuwied|Prince Maximilian]] and [[Karl Bodmer]] in 1834 being the most notable. In 1830 the [[American Fur Company]] established the [[Fort Clark Trading Post State Historic Site|Fort Clark Trading Post]] 40 miles upstream on the Missouri River to support trappers. To provide protection for the approaching rail line from the east and the homesteaders who would surely follow, the US Army established two outposts in the area in 1872 and 1873. Fort Greeley (later renamed Fort Hancock) was founded first on the river's east side. On the west side, an infantry post, Fort McKeen, was constructed on bluffs above the confluence of Heart and Missouri Rivers. In 1873 Congress authorized the addition of a cavalry post and changed its designation to [[Fort Abraham Lincoln]] when foot soldiers were deemed ineffective against their mounted adversaries. A permanent civilian settlement known as Lincoln was adjacent to the fort's north side.

When the Northern Pacific Railroad announced a pending river crossing in 1872, land speculators rushed to establish claims at probable locations for the inevitable city to be established on the west side of the crossing. But due to the national financial crisis in 1873, Northern Pacific postponed the river bridge project. Once its final location was announced, about five miles north of Fort Abraham Lincoln, a work camp appeared on the west riverbank in December 1878, complete with its own post office. The settlement also served as the base for the westward survey of the rail line.

On March 3, 1879, the post office was moved from the west bank of the Missouri River to the railroad's city site within blocks of Mandan's first railroad depot and freight building at Main Street and Stark Avenue (today's Collins Avenue). Four city names coincided exactly with four postmasters. The original railroad work camp's post office in 1878 was known as Morton. The name Mandan stuck for only eight days in March 1879 before being renamed Cushman by a postmaster with that surname. In September 1879, the post office returned to its designation of Mandan.<ref>{{cite book|last=Patera|first=Alan H.|title=North Dakota Post Offices 1850–1982|year=1982|publisher=The Depot, Burtonsville, Maryland|page=56}}</ref>

The City of Mandan was formally incorporated on February 24, 1881, and was named for the Mantani Indians, or "people of the bank." Mandan became the county seat for the replatted Morton County after the North Dakota legislature restored the prior county boundaries in 1881 after Burleigh County's land grab in 1879. The city of Lincoln had been county seat from 1878 to 1879.

Upon completion of the railroad to Montana in 1881, Fort Abraham Lincoln had fulfilled its primary purpose and gradually declined until it was formally abandoned in 1891. The City of Lincoln eventually dwindled into obscurity.