Research Findings: This study examined the contribution of several classroom experience measures (classroom characteristics, teacher characteristics, and teacher-child interactions) to preschoolers' improvement in visuomotor integration. Children (N = 467) ranged in age from 3 to 5 years old and were enrolled in 115 classrooms in 5 U.S. states. Children's visuomotor integration was measured twice (on average 5.2 months apart) using the Beery-Buktenica Developmental Test of Visual-Motor Integration (visuomotor integration subtest). Hierarchical linear models controlling for background characteristics and inhibitory control showed that children improved more in visuomotor integration when they were in classrooms with fewer 3-year-olds, when their teacher had at least a bachelor's degree, and when teachers demonstrated high quality in their interactions. Practice or Policy: Visuomotor integration, and specifically the ability to copy designs with a writing utensil, is a robust indicator of children's school readiness and longitudinal achievement. U.S. preschoolers gained more on visuomotor integration in classrooms with fewer 3-year-old children that were taught by a college-educated teacher and when such classrooms provided high-quality organizational and instructional interactions. These results expand the outcomes linked to early childhood education experiences and emphasize the need for well-prepared early childhood teachers who interact with children effectively.