In the present study, we present analyzed profiles of observed classroom experiences in terms of emotional and instructional dimensions of quality. Over 800 first-grade classrooms across the United States were included, selected by virtue of having a student participating in the National Institute of Child Health and Human Development's Study of Early Child Care and Youth Development enrolled in the classroom. Our aim was to present a typology of first grades. We examined correlates of classroom profiles in terms of teacher (years of experience, education, and beliefs), child (gender, ethnicity, family socioeconomic status, maternal education, and preschool achievement), and school (public vs. private, class size, presence of teachers' assistants) characteristics. Data were collected via teacher and parent questionnaires, classroom observations conducted by trained data collectors using the Classroom Observation System for First Grade, and individually administered child assessments (Woodcock Johnson Psycho-educational Battery Revised Tests of Cognitive Ability and Tests of Achievement). Findings indicated discernible, replicable types of first-grade classrooms (descriptively titled high quality, mediocre quality, low quality, and positive emotional climate/lower academic demand) that demonstrated different levels of emotional and instructional support and were related to several of the characteristics of children, families, teachers, and schools listed above. Of note, characteristics such as teachers' years of experience and class size were not differentially related to the four classroom types. (Contains 7 tables and 1 note.)