In 2010, the Common Core State Standards (CCSS) were adopted by most states in the US. The authors of these standards called for a shift from previous standards by recommending that young children experience a 50-50 balance between informational and literary reading. For this mixed-methods study, researchers examined the contents of 23 first-grade classroom libraries 8 years after the implementation of the CCSS to determine the percentage of expository texts found in these libraries and if these percentages differed based on the SES of the school or the number of years a teacher had been teaching. In addition, researchers interviewed twelve selected classroom teachers to gain an understanding of how they selected books for their libraries and what influenced their decisions. Results indicated that 22.8% of the texts found in first-grade classroom libraries were expository and there was no difference based on SES of the school or years a teacher had been in the classroom. Teacher interviews indicated that book cost, reading level, student interest, and genre (both narrative and expository/nonfiction) influenced their library text selections. Only two teachers indicated that the CCSS impacted their book choices.