Question: The county that Doris Beck was the first woman to serve as a Mayor of had a population of what in 2010?

Context paragraphs:
Doris Sands Johnson: Dame Doris Sands Johnson DBE (19 June 192121 June 1983) was a Bahamian teacher, suffragette, and politician.  She was the first Bahamian woman to contest an election in the Bahamas, the first female Senate appointee, and the first woman granted a leadership role in the Senate.  Once in the legislature, she was the first woman to be made a government minister and then was elected as the first woman President of the Senate.  She was the first woman to serve as Acting Governor General of the Bahamas, and was honored as Dame Commander of the Most Excellent Order of the British Empire by Queen Elizabeth II.

Frances E. Willis: Frances E. Willis (May 20, 1899, Metropolis IL – July 23, 1983, Redlands CA) was the third woman to enter the U.S. Foreign Service in 1927 and the first woman to make a career of the U.S. Foreign Service.  She held posts starting in Chile in 1928, then Sweden, Belgium and Spain during WW II, the U.S. State Department, England, Finland, Switzerland, Norway and Sri Lanka.  She was appointed ambassador to the last three posts, retiring at 65 from Sri Lanka in 1964.  During her Foreign Service career she became the first woman designated "chargé d'affaires", the first woman appointed deputy chief of mission, the first female Foreign Service officer (FSO) appointed ambassador, the first woman to serve as ambassador to three posts, the first woman appointed Career Minister in 1955 and the first woman appointed Career Ambassador in 1962 Career Ambassador.

Mazola McKerson: Mazola McKerson (January 10, 1921 – October 18, 2014) was the first of many things during her lifetime.  In 1977 she was elected to the Ardmore City County Commission, making her not only the first African-American, but also the first woman to serve on the City Council.  Only two years later, McKerson became the first African-American female mayor of Ardmore, Oklahoma, as well as the first woman in the United States to serve as mayor of a city of more than 30,000 people.  McKerson was also the first chairperson of the Governor's Commission on the Status of Women.  Aside from her public influence, McKerson owned and operated The Gourmet Restaurant in Ardmore from 1962 to 1997, the product of her home based catering company that she started in 1946.

Essex County, New Jersey: Essex County is a county in the northeastern part of the U.S. state of New Jersey.  As of the 2016 Census estimate, the county's population was 796,914, making it the state's third-most populous county, an increase of 1.7% from the 2010 United States Census, when its population was enumerated at 783,969, in turn a decrease of 1.2% (9,664 fewer residents) from the 793,633 enumerated in the 2000 Census.  In 2010, the county dropped down to third-largest, behind Middlesex County, and was one of only two counties in the state to see a decline between 2000 and 2010 (Cape May County being the other).  Its county seat is Newark.  It is part of the New York Metropolitan Area.

Charlotte Jones Anderson: Charlotte Jones Anderson (born July 26, 1966) is the Dallas Cowboys Executive Vice President and Chief Brand Officer.  Anderson was appointed Chairman of the Salvation Army’s National Advisory Board in 2010 and is the first woman to ever serve in that role.  In 2012, Anderson was named Chairman of the NFL Foundation and is responsible for spearheading philanthropic efforts in player care, youth football, and medical research.  Anderson is the first woman to serve in this capacity for an NFL charitable institution and the first woman to represent club ownership as leader of a major professional sports league foundation.

Doris Beck: Doris Lew Beck (born 1929) is an American Democratic Party politician who was the first woman to serve as Mayor of Livingston, New Jersey, and the first woman to serve as a Mayor in Essex County, New Jersey.  She was born in Chehanovietzer (Ciechanowiec), Poland, the daughter of Benjamin and Miriam Lew.  She worked as an English teacher and was the President of the League of Women Voters.  She was elected to the Livingston Township Council in 1974, defeating two Republican incumbents, and became Mayor in 1975.  She was re-elected in 1978.  She is the mother of WNBC-TV sports anchor Bruce Beck and married to her husband, Felix Beck, (1926-living), of 66 years.

Michelle D. Johnson: Michelle D. Johnson is a Lieutenant General in the United States Air Force and was the 19th Superintendent of the United States Air Force Academy.  She is the first woman to lead a United States Department of Defense Service Academy.  Her previous position was the Deputy Chief of Staff, Operations and Intelligence, Supreme Headquarters Allied Powers Europe in Casteau, Belgium.  She was formerly the Director, Strategy, Policy, Programs and Logistics, U.S. Transportation Command at Scott Air Force Base.  She also served as the deputy director for information and cyberspace policy, Strategic Plans and Policy Directorate at the Pentagon.  As an Air Force cadet, she was the first woman to serve as Cadet Wing Commander (the senior ranking cadet) at the United States Air Force Academy.  Johnson played basketball for the Air Force Falcons women's basketball team.  She was twice named an Academic All-American and was inducted into the Academic All-American Hall of Fame in 2007, making her the first woman from the Academy and one of only six graduates with that distinction.  Also, she was selected as the Academy's first woman Rhodes Scholar in her First Class (Senior) Year.  Johnson was recognized as an Honorary Fellow of Brasenose College in 2013.  She received the 2014 American Legion Auxiliary Woman of the Year Award.  Lt. General Johnson was awarded a star (#42) on The Flag for Hope on June 18, 2016 in recognition of her outstanding military service.

Doris Mahalick: Doris Meyer Mahalick (October 23, 1924 – October 17, 2008) was an American Democratic Party official who served on the Bergen County Board of Chosen Freeholders.  She served as the Mayor of Wallington, New Jersey and as the first woman to serve as the Bergen County Police Commissioner when she was appointed in 1965.  She was elected Freeholder in 1975, and was re-elected in 1978, 1981 and 1984.  She lost a bid for the New Jersey State Assembly in 1967.  In 1986, she sought the Democratic nomination for Bergen County Executive after voters changed the form of government; party leaders instead picked State Senator Matthew Feldman as their candidate.  She declined to seek re-election as Freeholder, and in the general election she endorsed Feldman's Republican opponent, William D. McDowell.  After McDowell won, Mahalick joined his administration.  She retired to Wildwood Crest, New Jersey and Palm Beach, Florida, and died in 2008 at age 83 after battles with Alzheimer's and Parkinson's diseases.

Lizette Parker: Lizette Parker (August 31, 1971 – April 24, 2016) was an American politician and social worker.  She served as the Mayor of Teaneck, New Jersey, from 2014 until her death in April 2016.  Parker was the first African-American woman to serve as Mayor of Teaneck, as well as the first African-American woman to serve as the mayor of any municipality in Bergen County, the state's most populous county.  Coincidentally, she succeeded former Mayor Mohammed Hameeduddin, who became the first Muslim to become the Mayor of a Bergen County community in 2010.

Pam Miller: Pam Miller served as the mayor of Lexington, Kentucky from 1993 to 2003.  On January 3, 1993, she became Lexington's first woman mayor.  She was first elected to the Urban County Council in 1973 and was the first woman elected to public office in the city.  She served from 1974 to 1977 and again from 1980 to 1993.  She served as vice-mayor before becoming mayor after the resignation of Scotty Baesler, who was elected to the United States Congress in 1992.  She was elected mayor in 1994 and again in 1998, though she chose not to run for a third full term in 2002.

Supporting paragraphs: Doris Beck Essex County, New Jersey
Answer: 783,969