Charles Jastrow Mendelsohn (December 8, 1880 – September 27, 1939) was an

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

cryptographer Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or ''-logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adver ...

and

classicist Classics or classical studies is the study of classical antiquity. In the Western world, classics traditionally refers to the study of Classical Greek and Roman literature and their related original languages, Ancient Greek and Latin. Classics ...

. He was the only child of

Rabbi A rabbi () is a spiritual leader or religious teacher in Judaism. One becomes a rabbi by being ordained by another rabbi – known as ''semikha'' – following a course of study of Jewish history and texts such as the Talmud. The basic form of ...

Samuel Mendelsohn Samuel Mendelsohn (1850–1922) was a Lithuanian Jewish rabbi and scholar born near Kaunas, Lithuania. Biography He was educated at the rabbinical college in Vilnius, at the rabbinic school in Berlin, and at Maimonides College, Philadelphia, P ...

and Esther Jastrow. He was born in

Wilmington, North Carolina Wilmington is a port city in and the county seat of New Hanover County in coastal southeastern North Carolina, United States. With a population of 115,451 at the 2020 census, it is the eighth most populous city in the state. Wilmington is the ...

Education

He graduated from the

Episcopal Academy The Episcopal Academy, founded in 1785, is a private, co-educational school for grades Pre-K through 12 based in Newtown Square, Pennsylvania. Prior to 2008, the main campus was located in Merion Station and the satellite campus was located in D ...

Philadelphia Philadelphia, often called Philly, is the largest city in the Commonwealth of Pennsylvania, the sixth-largest city in the U.S., the second-largest city in both the Northeast megalopolis and Mid-Atlantic regions after New York City. Sinc ...

in 1896. He was a Harrison Scholar at the

University of Pennsylvania The University of Pennsylvania (also known as Penn or UPenn) is a private research university in Philadelphia. It is the fourth-oldest institution of higher education in the United States and is ranked among the highest-regarded universitie ...

, which he graduated with a

Bachelor of Arts Bachelor of arts (BA or AB; from the Latin ', ', or ') is a bachelor's degree awarded for an undergraduate program in the arts, or, in some cases, other disciplines. A Bachelor of Arts degree course is generally completed in three or four years ...

in 1900 and a PhD in 1904. He was a member of

Phi Beta Kappa The Phi Beta Kappa Society () is the oldest academic honor society in the United States, and the most prestigious, due in part to its long history and academic selectivity. Phi Beta Kappa aims to promote and advocate excellence in the liberal a ...

. He joined the faculty of College of the City of New York as a tutor in Greek in 1905, becoming an instructor in 1907. He was a professor of ancient languages in 1917.

Military service

During

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

he served in the censorship department of the

Post Office Department The United States Post Office Department (USPOD; also known as the Post Office or U.S. Mail) was the predecessor of the United States Postal Service, in the form of a Cabinet department, officially from 1872 to 1971. It was headed by the postmas ...

in 1917, dealing with foreign language, postal and newspaper censorship. His work came to the attention of

Herbert Yardley Herbert Osborn Yardley (April 13, 1889 – August 7, 1958) was an American cryptologist. He founded and led the cryptographic organization the Black Chamber. Under Yardley, the cryptanalysts of The American Black Chamber broke Japanese diplomatic ...

and he was recruited into Military Intelligence, section 8 (MI-8). From 1918–19 he was a captain in the Military Intelligence Division of the

War Department War Department may refer to: * War Department (United Kingdom) * United States Department of War (1789–1947) See also * War Office, a former department of the British Government * Ministry of defence * Ministry of War * Ministry of Defence * Dep ...

General Staff. He led a team dealing with German diplomatic correspondence, breaking at least six diplomatic ciphers. Two messages dealt with German attempts to get support from Mexico. He received an

honorable discharge A military discharge is given when a member of the armed forces is released from their obligation to serve. Each country's military has different types of discharge. They are generally based on whether the persons completed their training and th ...

Return to civilian life

He returned to City College in 1920 as a professor of history. He remained interested in cryptography, writing papers and became interested in the history of the topic, collecting many books on it. He remained in contact with Herbert Yardley and did part time cryptographic work for the

Black Chamber The Black Chamber (1919–1929), also known as the Cipher Bureau, was the United States' first peacetime cryptanalytic organization, and a forerunner of the National Security Agency. The only prior codes and cypher organizations maintained by the ...

. Together they published the ''Universal Trade Code'', a commercial code. He wrote several works for the Black Chamber, including ''The Zimmermann Telegram of January 16, 1917, and its Cryptographic Background'' and ''Studies in German Diplomatic Codes Employed During the World War''.

Death

In 1939, he was recalled to active duty as a result of

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

, but while preparing he contracted

meningitis Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, headache, and neck stiffness. Other symptoms include confusion or ...

and died of it. His library, which had been called "probably the most important cryptographic library in America, if not in the world" was bequeathed to the University of Pennsylvania. He had never married and was survived by his mother. He was buried in the Hebrew Cemetery at Oakdale Cemetery, Wilmington, North Carolina.

Publications

*''Studies in the Word-Play in Plautus'' *''The Zimmermann Telegram of January 16, 1917, and its Cryptographic Background'' *''Studies in German Diplomatic Codes Employed During the World War''

References

{{DEFAULTSORT:Mendelsohn, Charles J. 1880 births 1939 deaths American cryptographers American people of Lithuanian-Jewish descent Burials at Oakdale Cemetery Jewish American writers Writers from Wilmington, North Carolina Deaths from meningitis American military personnel of World War I