Charles Allen graduated from Harvard College in 1847 and was admitted to the Northampton County bar in 1850. He became Reporter of Decisions in January, 1861, and remained in that office until April, 1867. His work was known for its clear conciseness, which proved invaluable in the Reporter's office and in all his other legal work, 214 Mass. 623 (1913). Known for a keen interest in business, Mr. Allen also developed an appreciation of the practical bearing of rules of law and their relevance to the conduct of business and the whole of society, 214 Mass. 619 (1913).

A notable change took place at the end of Mr. Allen's term in office as the Reporter: the reports, after 14 Allen, became known as the "Massachusetts Reports." The volumes published under Mr. Allen were the last to bear the name of the Reporter. His was the final name on the list that began with Octavius Pickering in 1822, 214 Mass. 614 (1913). These reports were not the only contribution Mr. Allen made to the literature of the law.

Mr. Allen compiled approximately 700 opinions as an Associate Justice of the Supreme Judicial Court, which appear throughout forty volumes of the Reports. He was also recognized for his work on the so-called Telegraph Cases, published in 1873, 214 Mass. 612 (1913). Mr. Allen was an admirer of Shakespeare's work. After retirement from the court, he published "Notes on the Bacon-Shakespeare Question."

After serving six years as Reporter, Mr. Allen was elected Attorney General of Massachusetts. After five years as Attorney General, and seven years in the general practice of law, Mr. Allen was appointed as an Associate Justice of the Court in 1882. He was the last survivor of his Harvard College class. He died on January 13, 1913, 214 Mass. 608, 609 (1913).