This dissertation is an analysis of the architecture, obsidian, ceramics, iron, and layout of Ciudad Vieja. The site is the remains of first successful town founded by the Spaniards in El Salvador. It was occupied from 1528 to 1545, a turbulent period of conquest before Spanish colonialism truly begins. It was an outpost of conquest occupied by Spaniards, their indigenous allies, and conquered locals as well as slaves brought from other parts of Central America. I began this study to investigate variation among the indigenous peoples living in the town to compare the strategies they employed to survive and in some cases take advantage of the new situation It quickly became apparent that identifying indigenous ethnic markers at the site was not a valid approach. Instead, I relied on the theoretical underpinnings of practice theory to try to compare groups at the household level. Colonial Spanish towns were planned as instruments of control, but Spanish interest ended at the solar boundary. The houses vary in scale and design between Spaniard and Indian, and to a lesser extent, variation exists within the Indian houses. Analysis of the pottery and obsidian yielded trends that imply the existence of different networks for raw material access (obsidian) and production (pottery). The presence of different nail types implies the existence of competing networks of trade. Differential access may have been influenced by access to Spanish trade goods, although differential access did not appear to affect the maintenance of cultural traditions. Household variation was also affected by class, with at least one structure apparently scavenging most of its material goods Ultimately, my analyses showed trends more than patterns, and more analysis will be required to verify these trends. I discovered which traits are the most salient to look for patterned variation and demonstrated the validity of using attribute analysis as the bridge from practice theory to data collection. Practice theory is a useful approach to frame research designs. The dynamism present in this town demonstrates the importance of studying the conquest period to better understand the culture change wrought by the colonialism that followed