Soil carbon sequestration, important to enhancing soil quality and mitigating the global climate change, depends on the amount of crop residue returned to the soil, availability of nitrogen (N) and other elements, and the attendant soil and crop management practices. Thus, this study was conducted with the objective of evaluating how soil organic carbon (SOC) and nitrogen (SON) changes with N fertilizer application in continuous corn (Zea mays) and two rotation treatments with corn and soybean (Glycine max) grown in alternate years. Replicated soil samples were collected from a long-term experiment (23-yr) at the Northwestern Agricultural Research and Demonstration Center, Monmouth, Illinois. The experimental design was split-split plot within a randomized complete block and the soil type is Mascatune silt loam. The five different rates of N applied annually to the plots were: (0 (N0), 70 (N1), 140 (N2), 210 (N3) and 280 (N4) kg N ha-1). Core samples were collected from each plot up to 90 cm depth and grouped into three depths: 0-30 cm, 30-50 cm and 50-90 cm. There was an increase in both SOC and SON pool with the addition of N fertilizers, with SOC pool ranging from 68.4 Mg ha-1 (N0) to 75.8 Mg ha-1 (N4) and SON pool ranging from 5.36 Mg ha-1 (N0) to 6.14 Mg ha-1 (N4) for 0-30 cm depth. The SOC sequestration rate over 23 years of N application ranged from 158 kg ha-1 yr-1 for 70 kg N ha-1 to 324 kg ha-1 yr-1 for 280 kg N ha-1 for 0-30 cm depth. Continuous corn increased 4.2 Mg ha-1 higher SOC sequestration in the top 30 cm depth compared to corn-soybean rotation. This study shows the important role of N fertilization and crop rotation in enhancing SOC pool, agronomic productivity and soil quality while mitigating the climate change.