Question: Fort Lyon was constructed south of a city whose population was what in the census of 2010?

Context paragraphs:
Sierra Madre, California: Sierra Madre is a city in Los Angeles County, California whose population was 10,917 at the 2010 U.S. Census, up from 10,580 at the time of the 2000 U.S. Census.  The city is located in the foothills of the San Gabriel Valley below the southern edge of the Angeles National Forest.  Pasadena and Altadena are to its west, with Arcadia to its south and east.  Sierra Madre is known as "Wisteria City", and its city seal is decorated with a drawing of the now widely known 500 ft vine.  It is also called the "Village of the Foothills" and was an All-America City in 2007.

Broadmayne: Broadmayne is a village in the English county of Dorset.  It lies within the West Dorset administrative district, two miles south-east of the county town Dorchester.  The A352 main road between Dorchester (from Sherborne) and Wareham passes through the village.  In the 2001 Census the population of the village was 1,864, reducing to 1,204 at the 2011 Census.  There is an electoral ward of the same name whose population at the above census was 1,870.  Village facilities and services include a Post Office, a clinic( now closed since 2014) and a public house ("The Black Dog").  There are two churches in the village, both of which were redesigned by Thomas Hardy.  The parish church of St. Martin dates from the 13th century and has a notable south tower.

James Brainard: James Brainard is the six-term mayor of Carmel, Indiana, a principal city in the Indianapolis metropolitan area.  Brainard has served 5 consecutive 4 year terms as the mayor of Carmel spanning 20 years.  In the Primary Election of 2015, he won his sixth term.  With his victory, Mayor Brainard is one of Indiana’s longest serving mayors.  For the past 20 years, he has led a city whose population has grown from 25,000 to more than 80,000.  His keynote projects have been the creation of a new downtown called City Center, where a new 1,600-seat concert hall, the Palladium, opened five years ago, the redevelopment of the oldest part of town into a new Arts & Design District and building several more city parks and trails.

Inkster, Michigan: Inkster is a city in Wayne County, Michigan, United States.  At the 2010 census, the city population was 25,369.  It is one of the few Metro Detroit suburbs whose population is majority African American.

South Lyon, Michigan: South Lyon is a city in Southwestern Oakland County in the U.S. state of Michigan, in Metro Detroit.  The population was 11,327 at the 2010 census.  The city is part of the South Lyon-Howell-Brighton Urban Area, which had a population of 106,139 according to the 2000 census.  South Lyon is located in Oakland County's Lyon Township, near the Livingston County and Washtenaw County lines.  The city is 19 mi north of Ann Arbor, 45 mi west of Detroit and 58 mi east of Lansing.

Nevada Senate: The Nevada Senate is the upper house of the Nevada Legislature, the state legislature of U.S. state of Nevada.  The Senate currently (2012-2021) consists of 21 members from single-member districts.  In the previous redistricting (2002-2011) there were 19 districts, two of which were multimember.  Since 2012, there have been 21 districts, each formed by combining two neighboring Assembly districts.  Each senator represented approximately 128,598 as of the 2010 census.  Article Four of The Nevada Constitution sets that Senators serve staggered four-year terms.  In addition, the size of the Senate is set to be no less than one-third and no greater than one-half of the size of the Assembly.  Term limits, limiting senators to three 4-year terms (12 years), took effect in 2010.  Because of the change in Constitution, seven senators were termed out in 2010, four were termed out in 2012, and one was termed out in 2014.  The Senate met at the Nevada State Capitol in Carson City until 1971, when a separate Legislative Building was constructed south of the Capitol.  The Legislative Building was expanded in 1997 to its current appearance to accommodate the growing Legislature.

Alexandria, Virginia: Alexandria is an independent city in the Commonwealth of Virginia in the United States.  As of the 2010 census, the population was 139,966, and in 2016, the population was estimated to be 155,810.  Located along the western bank of the Potomac River, Alexandria is approximately 7 mi south of downtown Washington, D.C.

Fort Lyon (Virginia): Fort Lyon (usually Camp Lyon in Northern records) was a timber and earthwork fortification constructed south of Alexandria, Virginia as part of the defenses of Washington, D.C. during the American Civil War.  Built in the weeks following the Union defeat at Bull Run, Fort Lyon was situated on Ballenger's Hill south of Hunting Creek, and Cameron Run (which feeds into it), near Mount Eagle (plantation).  From its position on one of the highest points south of Alexandria, the fort overlooked Telegraph Road, the Columbia Turnpike, the Orange and Alexandria Railroad, the Little River Turnpike, and the southern approaches to the city of Alexandria, the largest settlement in Union-occupied Northern Virginia.

Harlem riot of 1935: The Harlem riot of 1935 took place on March 19 during the Great Depression, in New York City, New York, in the United States.  It has been described as the first "modern" race riot in Harlem, because it was committed primarily against property rather than persons.  Harlem is a northern neighborhood on Manhattan island in New York City whose population at the time was predominately African American.  The rioting did not feature two ethnic groups in conflict.

Woodbury, Devon: Woodbury is a village and civil parish in East Devon in the English county of Devon, 7 mi south east of the city of Exeter.  It is a commuter village and is primarily residential, since the majority of the workforce commute to Exeter.  The parish, which has a population of 3,466 recounted for the village alone of 1,605 at the 2011 Census, lies on the east bank of the Exe Estuary, has borders – clockwise from the estuary – with the district of Exeter (near to Topsham) and then the parishes of Clyst St George, Clyst St Mary, Farringdon, Colaton Raleigh, Bicton and Lympstone.  "Woodbury" is part of the electoral ward of "Woodbury" and Lympstone whose population at the 2011 Census was 5,260.

Supporting paragraphs: Fort Lyon (Virginia) Alexandria, Virginia
Answer: 139,966