The city was considered part of the early 20th century Gold Coast of the North Shore, as the areas along the waterfront were developed as large country estates by wealthy entrepreneurs and businessmen such as J.P. Morgan, Phipps, Pratt, and Prybil. Glen Cove also had manufacturing and a diverse population that worked in industry, local agriculture and retail businesses. Of Nassau County’s five municipalities, Glen Cove is one of the two municipalities that is a city, rather than a town, the other being Long Beach.
The city was the location of several successful manufacturing facilities in the 20th century. It attracted numerous immigrants from Ireland, Italy, and eastern Europe. More recently, it has been settled by immigrants of later migrations, from Central and South America, and Asia.