 The longest article, on the United States, resulted from the merging of the 50 articles on each state.The articles of the "Macropædia" are generally written by named contributors and have references, in contrast to the roughly 65,000 articles of the "Micropædia" that have no named contributor and no references.However, some parts of the "Macropædia" were written by the editorial staff of the "Britannica"; such editorial articles are identified by the initials "Ed."