We computed mean inbreeding coefficients (F_IT, F_IS, and F_ST) based on approximately 2,700 ascending pedigrees of contemporary people from Saguenay Lac-St-Jean (Québec, Canada). This allowed us to appreciate the accumulated inbreeding and to follow the evolution of these coefficients since the founding of Québec. One of the results was the expected increase in F_ST. Relying on this parameter, we computed the effective size (N_e) of the contemporary population, obtaining a value around 1,000, in agreement with previous estimations. We noticed a decrease of N_e through history despite the population's growing size.