In this first chapter of empirical findings, we provide an overview of trends and patterns in the residential segregation of households by race and ethnicity from 1990 to 2010 across metropolitan areas, micropolitan areas, and noncore counties. These three community types give our analysis wide geographic coverage across the United States. We examine segregation between White, Black, Asian, and Latino households across all areas over the two decades bracketed by the three decennial census years of 1990, 2000, and 2010. What distinguishes the analyses in this chapter from previous studies is that we apply new methods for measuring residential segregation which include correcting for index bias, using a measure that is better suited for distinguishing between different patterns of uneven distribution, and measuring residential segregation of households rather than persons. These adjustments allow us to expand the scope of our analysis to include more communities beyond the largest metropolitan areas while measuring residential segregation at the block-level, which is necessary for measuring segregation in less densely populated areas. While our findings at times reflect what past studies have found, it is more often the case that we reveal different levels and patterns of segregation, especially when focusing on White-Latino and White-Asian segregation where patterns of uneven distribution are more dispersed than previously understood. This first empirical chapter sets new benchmarks for residential segregation measurement and analysis in U.S. communities.