Lawnside is a borough in Camden County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 2,945, reflecting an increase of 253 from the 2,692 counted in the 2000 Census. In the previous decade, the population of the small community had declined by 149 from the 2,841 counted in the 1990 Census.Lawnside was developed and incorporated as the first independent, self-governing black municipality north of the Mason-Dixon Line in 1840. The United Parcel Service has a large depot in the borough.