Colorado

Arapahoe

655,070

2020 population

1870

first census record

census records

About Arapahoe

Arapahoe, Colorado, first appears in the United States federal census in 1870, when it recorded a population of 6,829. At the most recent census, in 2020, its population stood at 655,070.

The county's recorded population has risen across the decades to its highest level in 2020.

On the ground today, 3 documented military engagements have been recorded within the county, among them Hungate Massacre — Colorado (June 11, 1864), Arapaho Raids on Denver Road 1864, Battle of Valley Station, and 25 places are listed on the National Register of Historic Places.

Population by decade

Census Year	Population	Chart
2020	655,070
2010	572,003
2000	487,967
1990	391,511
1980	293,621
1970	162,142
1960	113,426
1950	52,125
1940	32,150
1930	22,647
1920	13,766
1910	10,263
1900	153,017
1890	132,135
1880	38,644
1870	6,829

Source

Population data from the United States decennial census, U.S. Census Bureau (public domain).

Battles & engagements in Arapahoe

Military engagements that took place in Arapahoe, Colorado.

Hungate Massacre — Colorado (June 11, 1864)

1864

Arapaho Raids on Denver Road 1864

1864

Battle of Valley Station

1865

Historic places in Arapahoe

National Register of Historic Places listings in Arapahoe, Colorado.

Geneva Home

Littleton

Smith, William, House

Littleton Main Street

Comanche Crossing of the Kansas Pacific Railroad

Strasburg

Brown, David W., House

Englewood

Littleton Town Hall

Littleton

Browse all Coloradohistoric sites ›

Other counties in Colorado

Explore census history and historic records for more Colorado counties.

Jackson Jefferson Kiowa Kit Carson La Plata Lake Larimer Las Animas Lincoln Logan Mesa Mineral Moffat Montezuma Montrose Morgan Otero Ouray Park Phillips

Unlimited access

Everything a full report reveals about Arapahoe County, Colorado

This page charts the census history of Arapahoe County, Colorado. A full Aubrey report for an address here pulls together everything the historical record holds about the ground, from the earliest settlement to the twentieth century:

Overview

An interactive map of the location with historic sites, battles and Native heritage plotted, and its full story era by era.

The Land

The historic sites and place names around the location, and how this land was settled and used.

Geology

The bedrock beneath the site, its age and rock type, reaching back millions of years.

LiDAR Terrain

Laser-scanned terrain that reveals earthworks and old features hidden in the landscape.

Conflict & War

The battles, raids and skirmishes fought near here, across every era of American conflict.

The Civil War

The Civil War on this ground, 1861 to 1865: who held it, and the battles, camps and regiments nearby.

The Soldiers

The men who marched from here in the Civil War, named and traced where the record allows.

Native Heritage

The Native nations who held this land, mapped across time from before European contact to today.

Settlement

Who claimed and held this ground, from Indigenous homelands through the colonial powers to the United States.

The Community

How the town grew, who came, and what kind of place it became, traced through the census record.

Rivers & Rail

The rivers, canals and railroads that connected this place between 1830 and 1911.

Notable People

The people born, buried or genuinely tied to this exact place, with their stories.

Historical Maps

Historic maps of the location layered over how it looks today.

Finds & Access

Museum objects tied to the area, and the laws on searching, collecting and access here.

Literature

The old books, county histories and archives that mention this place, quoted with their sources.

Spotlight

A deep dive into the most remarkable, lesser-known history of the place, traced back to the record.

Points of Interest

The most significant historic sites and landmarks near the location, and why they matter.

Timeline

The whole story of the location told era by era, from first peoples to the present day.

First month just $5.99, then $11.99 a month. Unlimited locations, cancel anytime.

Every location is different. Not every section appears for every place, only what the historical record actually holds turns up in a report.

Start your Arapahoe County, Colorado report

Or see a real report first

Explore Colorado records

Coloradohistory ›NRHP historic sites ›Notable people from Colorado›

Frequently asked about Arapahoe

When does Arapahoe first appear in the US census?

Arapahoe, Colorado first appears in the federal census in 1870, with a recorded population of 6,829.

What is the population of Arapahoe?

At the most recent federal census (2020), Arapahoe had a recorded population of 655,070.

Were any battles fought in Arapahoe?

3 documented military engagements took place in Arapahoe, including Hungate Massacre — Colorado (June 11, 1864), Arapaho Raids on Denver Road 1864, Battle of Valley Station.

How many historic places are in Arapahoe?

25 sites are listed on the National Register of Historic Places in Arapahoe, Colorado.

Aubrey Research

Research the history of any US location

Aubrey searches federal archives, archaeological records, historic registers, and primary sources to build a full historical report for any address or place in the United States.

Research your location View a free sample report