The first edition of the Merriam-Webster thesaurus was published in 1976 under the title of "Webster's Collegiate Thesaurus." The second edition, entitled "Merriam-Webster's Collegiate Thesaurus," was published in 2010.
The vocabulary in this second edition of the thesaurus is taken from the 11th edition of Merriam-Webster's Collegiate Dictionary.
Noah Webster wrote his dictionary in 1841; the rights to this and subsequent editions were acquired by printing and bookselling company G. & C. Merriam Co. two years later. G. & C. Merriam Co. started selling the dictionary on September 24, 1847, for $6. The company was renamed Merriam-Webster, Inc. in 1982.