The American sociologist who focused on social analysis, developing abstract models showing how parts of society harmoniously work together, was .

Talcott Parsons

Explanation:

Talcott Parsons is an American 20th century sociologist known for the development of a social school of thought which focused on problems of social order, integration, and equilibrium through the social analysis of the society as a functional whole. His social action theory explains how structures of a social system are formed to develop and maintain  social system, through the interaction of units that are interrelated.