Oklahoma's universal pre-K (UPK) program has long been a classic "man bites dog" story. In 1998, Oklahoma became the second state in the U.S. to offer free pre-K to all four-year-olds. Coupled with growing evidence of the critical importance of the early years in brain synapse formation, results like Tulsa's have encouraged state and federal officials elsewhere to consider UPK. In separate studies of students about to begin kindergarten and students about to begin preschool in the fall of 2001, 2003, and 2006, the author found that the TPS UPK program produced big gains in school readiness for both disadvantaged and middle-class students. The author added Head Start to the mix in 2006. Head Start's performance was also impressive, though the verbal gains were a bit weaker than those for TPS. To study longer-term effects, we focused on 4,033 TPS kindergarten entrants in the fall of 2006. States that opt for universal pre-K should make sure that the benefits of universal coverage are fully realized by mixing students from different socioeconomic brackets in the same classroom. All states should ensure that pre-K classrooms are staffed by well-educated, well-paid teachers who have credentials in early childhood education.