Around 1914 Latin America was widely understood to be a Catholic continent, and Catholic propagandists depicted it as the beneficiary of sustained missionary endeavour during the colonial period. This orthodoxy seemed confirmed by national censuses, which routinely identified over 90 per cent of the populations of various countries as Catholic. Protestant missionaries, reaffirming these simplicities, viewed themselves as championing a heroic struggle against ‘Romish domination’. The reality was different: more subtle, diverse and complex. The spatial impact of the Catholic church was never uniform, being more pronounced in upland areas of relatively dense settlement than in the more sparsely inhabited lowlands. The social significance of the Catholic church varied considerably between and within social classes and ethnic groups. Profound and nominal commitment, indifference, suspicion and unalloyed hostility were all observed. The political influence of Catholicism varied by nation, region and municipality, according to specific experiences of regalism, independence and civil war, and the impact of secularising ideologies. The direction of change in Christianity across Latin America over the first half of the twentieth century was broadly the same, but its pace was never uniform. Domestic trends interacted with external influences to produce a richly heterogeneous picture, which often defies generalisation. Thus the record of the Catholic church in catechisation was patchy, as was its distribution of institutional resources. The limits to formal Catholic influence were observed in low rates of church marriage over vast areas. In many dioceses more effort was invested by the bishops in obstructing legislation for civil marriage and divorce that interested small minorities than in assuring effective ratios of clergy to parishioners.