This paper presents the estimates of the gross domestic product (GDP) of the Congress Kingdom of Poland for the period 1870–1912. The authors used bottom-up methodology and calculated sectoral added values using historical economic, social, and demographic data. The presented results offer first ever insight into the structure of sectoral added values in the Congress Kingdom of Poland during the period of first globalization and first reliable estimates of GDP of the Congress Kingdom of Poland. All results are presented in Geary–Khamis dollars PPP1990 and are compatible with Maddison dataset.