Elsmere is a town in New Castle County, Delaware, United States, bordering the city of Wilmington along Wilmington's western border. According to the 2010 Census, the population of the town is 6,131. Elsmere dates back to 1886 when real estate developer Joshua Heald bought farmland and converted it into houses, building the first subur…Elsmere is a town in New Castle County, Delaware, United States, bordering the city of Wilmington along Wilmington's western border. According to the 2010 Census, the population of the town is 6,131. Elsmere dates back to 1886 when real estate developer Joshua Heald bought farmland and converted it into houses, building the first suburb in northern Delaware. The community was built at an intersection of railroad lines and allowed working-class families easy access to Wilmington. Trolley lines were later built leading to Elsmere. In 1909, Elsmere was incorporated as a town.