State of the FieldThe teaching of world history expanded dramatically in the United States in the 1990s, when most states adopted curricula requiring the teaching of world history in high schools and middle schools. From 2000, the College Boardâ€™s AP World History course (providing a college-level course for high school students) rapidly became one of the largest AP courses. Meanwhile, the general world history course at the secondary level has not benefited from additional resources since the 1990s. Curriculum in world history is expanding in countries around the world. The World History Network seeks to keep track of developments in the teaching of world history in all regions of the world, and at secondary and post-secondary levels.