Atlantic is a city in, and the county seat of, Cass County, Iowa, United States,  located along the East Nishnabotna River. The population was 7,112 in the 2010 census, a decline from the 7,257 population in the 2000 census.  
Atlantic was founded in October 1868 by Franklin H. Whitney, B.F. Allen, John P. Cook, and others. While historians cannot agree how Atlantic got its name, local legend tells that the founding fathers estimated that the town was about halfway between the Pacific Ocean and the Atlantic Ocean, so it led them to flip a coin and, clearly, Atlantic won. The nearby Rock Island Railroad was important in deciding the actual location of the town, and to this day, the old depot sits at the north end of Chestnut Street. Today, the old depot serves as the offices of the Chamber of Commerce. 
|“||A Link With the Past (Quote from the plaque in front of the cabin.)
Another story told about Atlantic is the way main street was located. Someone asked Whitney where it should be placed. He marked the center at current day 6th and Chestnut and then plowed two furrows 100 feet (30 m) apart all the way up to the railroad, just north of Second Street. 
Atlantic's longitude and latitude coordinates in decimal form are 41.401404, -95.010867. 
According to the United States Census Bureau, the city has a total area of 8.35 square miles (21.63 km2), of which, 8.32 square miles (21.55 km2) is land and 0.03 square miles (0.08 km2) is water. 
|U.S. Decennial Census |
As of the census  of 2010, there were 7,112 people, 3,137 households, and 1,906 families residing in the city. The population density was 854.8 inhabitants per square mile (330.0/km2). There were 3,399 housing units at an average density of 408.5 per square mile (157.7/km2). The racial makeup of the city was 97.0% White, 0.2% African American, 0.3% Native American, 0.3% Asian, 0.5% Pacific Islander, 1.0% from other races, and 0.6% from two or more races. Hispanic or Latino of any race were 2.6% of the population.
There were 3,137 households of which 26.8% had children under the age of 18 living with them, 47.0% were married couples living together, 9.9% had a female householder with no husband present, 3.9% had a male householder with no wife present, and 39.2% were non-families. 34.3% of all households were made up of individuals and 15.7% had someone living alone who was 65 years of age or older. The average household size was 2.21 and the average family size was 2.80.
The median age in the city was 44.3 years. 22.6% of residents were under the age of 18; 7.1% were between the ages of 18 and 24; 20.9% were from 25 to 44; 27.1% were from 45 to 64; and 22% were 65 years of age or older. The gender makeup of the city was 47.9% male and 52.1% female.
As of the census  of 2000, there were 7,257 people, 3,126 households, and 1,969 families residing in the city. The population density was 890.4 people per square mile (343.8/km²). There were 3,354 housing units at an average density of 411.5 per square mile (158.9/km²). The racial makeup of the city was 98.65% White, 0.25% African American, 0.12% Native American, 0.22% Asian, 0.06% Pacific Islander, 0.41% from other races, and 0.29% from two or more races. Hispanic or Latino of any race were 0.79% of the population.
There were 3,126 households out of which 28.5% had children under the age of 18 living with them, 51.0% were married couples living together, 8.8% had a female householder with no husband present, and 37.0% were non-families. 33.7% of all households were made up of individuals and 18.0% had someone living alone who was 65 years of age or older. The average household size was 2.22 and the average family size was 2.81.
Age spread: 23.0% under the age of 18, 7.4% from 18 to 24, 24.3% from 25 to 44, 22.3% from 45 to 64, and 23.0% who were 65 years of age or older. The median age was 42 years. For every 100 females, there were 89.3 males. For every 100 females age 18 and over, there were 83.5 males.
The median income for a household in the city was $33,370, and the median income for a family was $41,168. Males had a median income of $30,691 versus $20,271 for females. The per capita income for the city was $17,832. About 6.3% of families and 12.1% of the population were below the poverty line, including 17.5% of those under age 18 and 10.6% of those age 65 or over.
Atlantic, Iowa is one of the smallest communities in Iowa to have a daily newspaper, The Atlantic News Telegraph. The editor E.P. Chase of the newspaper was awarded the 1934 Pulitzer Prize for Editorial Writing.
Atlantic is home to three radio stations. KJAN 1220 AM which features a variety music format and is licensed to Wireless Communications Corp.. KJAN also broadcasts on FM translator 101.1. KJAN AM 1220/FM 101.1 features local news, sports, weather, farm and information 24 hours a day. Listen to Iowa Hawkeye football and basketball, St. Louis Cardinals baseball and Kansas City Chiefs football on KJAN. KSOM 96.5 FM which features country music, Paul Harvey, Farm Reports, the Local News, Iowa State Sports and NASCAR. KSWI 95.7 FM which features classic rock and Atlantic high school sports. Meredith Communications, LLC currently (2010) owns both KSOM and KSWI.
- Don A. Allen, member of California State Assembly and of Los Angeles City Council in 1940s and 1950s, born in Atlantic  
- Harlan J. Bushfield (1882–1948), Republican U.S. senator and 16th governor of South Dakota
- Blake Curd (born 1967), Physician and South Dakota state legislator
- Jack Drake (1934-2015), longtime state representative in Iowa, born and died in Atlantic
- William G. Cambridge, United States federal court judge
- Steve H. Hanke, professor of economics, adviser to presidents, currency reformer and commodity and currency trader
- Frederick C. Loofbourow (1874–1949), Republican U.S. representative from Utah
- Shannon McCormick (born 1971), actor and voice actor
- Ethel T. Wead Mick (1881–1957), founder of Masonic girls' organization now known as Job's Daughters
- Ed Podolak (born 1947), professional football player and color commentator for Iowa Hawkeyes football games on WHO radio
- William Appleman Williams (1921–1990), president of Organization of American Historians
- Lafayette Young (1848–1926), Republican senator from Iowa, state senator, newspaper reporter, editor and owner
- "US Gazetteer files 2010". United States Census Bureau. Archived from the original on 2012-01-24. Retrieved 2012-05-11.
- "American FactFinder". United States Census Bureau. Retrieved 2012-05-11.
- "Population and Housing Unit Estimates". Retrieved June 9, 2017.
- "Find a County". National Association of Counties. Archived from the original on 2011-05-31. Retrieved 2011-06-07.
- "Population & Housing Occupancy Status 2010". United States Census Bureau American FactFinder. Archived from the original on 26 July 2011. Retrieved 2011-08-06.
- "Data from the 2010 Census". State Data Center of Iowa. Archived from the original on 26 July 2011. Retrieved 2011-08-06.
- * Naming of Atlantic" Archived May 9, 2008, at the Wayback Machine.
- Quote from the plaque in front of the cabin.
- Atlantic Bottling Company - About Us
- "US Gazetteer files: 2010, 2000, and 1990". United States Census Bureau. 2011-02-12. Retrieved 2011-04-23.
- "Census of Population and Housing". Census.gov. Archived from the original on May 12, 2015. Retrieved June 4, 2015.
- "American FactFinder". United States Census Bureau. Archived from the original on 2013-09-11. Retrieved 2008-01-31.
- Los Angeles Public Library reference file
- JoinCalifornia website, citing other sources
|Wikimedia Commons has media related to Atlantic, Iowa.|
|Wikisource has the text of the 1905 New International Encyclopedia article Atlantic.|
- Official Atlantic City Website
- Chamber of Commerce
- Atlantic News Telegraph Local daily newspaper website
- Atlantic Police Department
- City Data Detailed Statistical Data and more about Atlantic, Iowa