To determine which decade witnessed the least movement of the United States’ center of population according to the described migration waves on the map, we can analyze the waves chronologically:
- Hugging the Coast (1790) - The first wave of migration.
- Crossing the Appalachians (1800–1840) - Increases migration towards the west.
- Rushing to the Gold (1850–1890) - Suggests significant movement towards the west in pursuit of gold, especially during the 1850s.
- Filling in the Great Plains (1900–1940) - Indicates further migration westward and southward.
- Moving South (1950–2010) - Displays continued movement but mostly south.
Considering the decades of specific movements: the 1810s and 1820s fall into the early expansion phase (Crossing the Appalachians), but the migrations might not have been as significant as those seen in the 1850s and later in the next waves.
Since the 1830s saw significant westward expansion, notably due to the Gold Rush, and the 1920s saw both migration and economic changes, we should consider the 1810s and 1820s as potential lower movement periods.
From this breakdown, the decade that witnessed the least movement of the United States’ center of population is likely the 1820s.