This paper is an examination of statewide district writing achievement gain data from the Nebraska Statewide Writing Assessment system and implications for statewide assessment writing models. The writing assessment program is used to gain compliance with the United States No Child Left Behind Law (NCLB), a federal effort to influence school district assessment and accountability. While the research literature is mixed with some viewing statewide writing assessment as narrowing writing curriculum and ''standardizing'' writing, others point out that it facilitates sharing between teachers to improve writing and teachers are empowered by their participation in the process. Nebraska's Statewide Writing Assessment, based on the six-trait model, has strong support from teachers regarding their perception of the assessment in supporting teaching practices and student success. Examination of achievement gain data revealed gains in 4th, 8th, and 11th grades in the average number of students rated proficient from one administration of the assessment to the next. Implications for educational practice, recommendations for future research, and relevant related issues (NCLB concerns and measurement issues) are discussed. (Contains 3 tables.)