* State governments: State-level departments of education often establish broad curriculum standards and frameworks, outlining what students should know and be able to do at each grade level in different subjects. These standards are often based on national standards but are tailored to the state's context and priorities.
* Local school districts: School districts take the state standards and translate them into specific curriculum materials, teaching plans, and assessments. They may adopt pre-made curricula from publishers or create their own.
* School administrators and teachers: Principals and teachers play a crucial role in adapting the district curriculum to their specific school and student populations. They select textbooks, design lesson plans, and make adjustments based on student needs and performance.
* Textbook publishers and educational companies: These entities create and sell the textbooks, learning materials, and software used in schools. While they don't set the curriculum itself, the content and organization of their materials significantly influence how it's implemented.
* Federal government: The federal government's role is generally limited to providing funding and setting broad national goals, but they don't directly dictate curriculum. However, federal legislation like the Every Student Succeeds Act (ESSA) influences state and local curriculum decisions.
In short, it's a collaborative and layered process, with different levels of government and educational professionals contributing to the final curriculum implemented in each school.