In this paper, we employ parametric and nonparametric techniques to analyse the effect of market potential on the structure and growth of Spanish cities during the period 1860-1960. Even though a few attempts have been made to analyse whether market potential might influence urban structures, this period is especially interesting because it is characterised by advances in the economic integration of the national market together with an intense process of industrialisation. By using an elaborated measure of market potential at the city level, our results show a positive influence of this market potential on city growth, although this influence is heterogeneous over time. Only changes in the market potential from 1900 have a significant effect on population growth.