The village's population growth has been robust. In the 1990 U.S. Census, Oswego 's population stood at 3,875. Just seven years later, a special census showed its population had risen above 9,000, finally surpassing Boulder Hill and making it the largest community in Kendall County . In the 2000 census, Oswego 's population had grown to 13,326. Four years later, a special census counted nearly 20,000 residents living in Oswego 's municipal limits. As Oswego continues to grow, its location on two rail lines, three state highways, and two U.S. highways, along with its continuing economic development and growth, the village is experiencing a period of rapid economic and population growth very similar to that which took place right after Judson and Arnold laid out their new town 160 years ago.