The American Journal of Science (AJS), founded in 1818 by Benjamin Silliman, is the oldest scientific journal in the United States that has been published continuously. The Journal is devoted to geology and related sciences and publishes articles from around the world presenting results of major research from all earth sciences. Readers are primarily earth scientists in academia and government institutions. AJS had an impact factor of 3.566 and a five year impact factor of 4.217 for 2015, ranking near the top for all peer-reviewed earth sciences journals publishing new content. Articles in AJS tend to be cited for many years, resulting in a citation half-life that exceeds 10 years (all statistics from Thomson ISI).