Webster lacked career plans after graduating from Yale in 1779, later writing that a liberal arts education “disqualifies a man for business”. He taught school briefly in Glastonbury, but the working conditions were harsh and the pay low. He quit to study law. While studying law under future U.S. Supreme Court Chief Justice Oliver Ellsworth, Webster also taught full-time in Hartford—which was grueling, and ultimately impossible to continue. He quit his legal studies for a year and lapsed into a depression; he then found another practicing attorney to tutor him, and completed his studies and passed the bar examination in 1781. As the Revolutionary War was still going on, he could not find work as a lawyer. He received a master’s degree from Yale by giving an oral dissertation to the Yale graduating class. Later that year, he opened a small private school in western Connecticut that was a success. Nevertheless, he soon closed it and left town, probably because of a failed romance. Turning to literary work as a way to overcome his losses and channel his ambitions, he began writing a series of well-received articles for a prominent New England newspaper justifying and praising the American Revolution and arguing that the separation from Britain would be a permanent state of affairs. He then founded a private school catering to wealthy parents in Goshen, New York and, by 1785, he had written his speller, a grammar book and a reader for elementary schools. Proceeds from continuing sales of the popular blue-backed speller enabled Webster to spend many years working on his famous dictionary.

Webster’s Speller was entirely secular by design. It ended with two pages of important dates in American history, beginning with Columbus’s discovery of America in 1492 and ending with the battle of Yorktown in 1781. There was no mention of God, the Bible, or sacred events. “Let sacred things be appropriated for sacred purposes,” wrote Webster. As Ellis explains, “Webster began to construct a secular catechism to the nation-state. Here was the first appearance of ‘civics’ in American schoolbooks. In this sense, Webster’s speller becoming what was to be the secular successor to The New England Primer with its explicitly biblical injunctions.” Later in life, Webster became intensely religious and added religious themes. However, after 1840, Webster’s books lost market share to the McGuffey Eclectic Readers of William Holmes McGuffey, which sold over 120 million copies.

The speller was originally titled The First Part of the Grammatical Institute of the English Language. Over the course of 385 editions in his lifetime, the title was changed in 1786 to The American Spelling Book, and again in 1829 to The Elementary Spelling Book. Most people called it the “Blue-Backed Speller” because of its blue cover and, for the next one hundred years, Webster’s book taught children how to read, spell, and pronounce words. It was the most popular American book of its time; by 1837, it had sold 15 million copies, and some 60 million by 1890—reaching the majority of young students in the nation’s first century. Its royalty of a half-cent per copy was enough to sustain Webster in his other endeavors. It also helped create the popular contests known as spelling bees.

Webster dedicated his Speller and Dictionary to providing an intellectual foundation for American nationalism. From 1787 to 1789, Webster was an outspoken supporter of the new Constitution. In October 1787, he wrote a pamphlet entitled “An Examination into the Leading Principles of the Federal Constitution Proposed by the Late Convention Held at Philadelphia,” published under the pen name “A Citizen of America.” The pamphlet was influential, particularly outside New York State.

Noah Webster married Rebecca Greenleaf (1766–1847) on October 26, 1789, New Haven, Connecticut. They had eight children:

Webster helped found the Connecticut Society for the Abolition of Slavery in 1791, but by the 1830s rejected the new tone among abolitionists that emphasized that Americans who tolerated slavery were themselves sinners. In 1837, Webster warned his daughter Eliza about her fervent support of the abolitionist cause. Webster wrote, “slavery is a great sin and a general calamity—but it is not our sin, though it may prove to be a terrible calamity to us in the north. But we cannot legally interfere with the South on this subject.” He added, “To come north to preach and thus disturb our peace, when we can legally do nothing to effect this object, is, in my view, highly criminal and the preachers of abolitionism deserve the penitentiary.”

Webster married well and had joined the elite in Hartford but did not have much money. In 1793, Alexander Hamilton lent him $1,500 to move to New York City to edit the leading Federalist Party newspaper. In December, he founded New York’s first daily newspaper American Minerva (later known as the Commercial Advertiser), which he edited for four years, writing the equivalent of 20 volumes of articles and editorials. He also published the semi-weekly publication The Herald, A Gazette for the country (later known as The New York Spectator).

For decades, he was one of the most prolific authors in the new nation, publishing textbooks, political essays, a report on infectious diseases, and newspaper articles for his Federalist party. He wrote so much that a modern bibliography of his published works required 655 pages. He moved back to New Haven in 1798; he was elected as a Federalist to the Connecticut House of Representatives in 1800 and 1802–1807.

Webster was elected a Fellow of the American Academy of Arts and Sciences in 1799.

In 1806, Webster published his first dictionary, A Compendious Dictionary of the English Language. In 1807 Webster began compiling an expanded and fully comprehensive dictionary, An American Dictionary of the English Language; it took twenty-six years to complete. To evaluate the etymology of words, Webster learned twenty-eight languages, including Old English, Gothic, German, Greek, Latin, Italian, Spanish, French, Dutch, Welsh, Russian, Hebrew, Aramaic, Persian, Arabic, and Sanskrit. Webster hoped to standardize American speech, since Americans in different parts of the country used different languages. They also spelled, pronounced, and used English words differently.

Webster in early life was something of a freethinker, but in 1808 he became a convert to Calvinistic orthodoxy, and thereafter became a devout Congregationalist who preached the need to Christianize the nation. Webster grew increasingly authoritarian and elitist, fighting against the prevailing grain of Jacksonian Democracy. Webster viewed language as a tool to control unruly thoughts. His American Dictionary emphasized the virtues of social control over human passions and individualism, submission to authority, and fear of God; they were necessary for the maintenance of the American social order. As he grew older, Webster’s attitudes changed from those of an optimistic revolutionary in the 1780s to those of a pessimistic critic of man and society by the 1820s.

He moved to Amherst, Massachusetts in 1812, where he helped to found Amherst College. In 1822 the family moved back to New Haven, where Webster was awarded an honorary degree from Yale the following year. He is buried in New Haven’s Grove Street Cemetery.

Webster completed his dictionary during his year abroad in January 1825 in a boarding house in Cambridge, England. His book contained seventy thousand words, of which twelve thousand had never appeared in a published dictionary before. As a spelling reformer, Webster preferred spellings that matched pronunciation better. In A Companion to the American Revolution (2008), John Algeo notes: “It is often assumed that characteristically American spellings were invented by Noah Webster. He was very influential in popularizing certain spellings in America, but he did not originate them. Rather … he chose already existing options such as center, color and check on such grounds as simplicity, analogy or etymology.” He also added American words, like “skunk”, that did not appear in British dictionaries. At the age of seventy, Webster published his dictionary in 1828, registering the copyright on April 14.

His 1828 American Dictionary contained the greatest number of Biblical definitions given in any reference volume. Webster said of education,

Webster released his own edition of the Bible in 1833, called the Common Version. He used the King James Version (KJV) as a base and consulted the Hebrew and Greek along with various other versions and commentaries. Webster molded the KJV to correct grammar, replaced words that were no longer used, and did away with words and phrases that could be seen as offensive.

In 1834, he published Value of the Bible and Excellence of the Christian Religion, an apologetic book in defense of the Bible and Christianity itself.

In 1840, the second edition was published in two volumes. On May 28, 1843, a few days after he had completed revising an appendix to the second edition, and with much of his efforts with the dictionary still unrecognized, Noah Webster died. The rights to his dictionary were acquired by George and Charles Merriam in 1843 from Webster’s estate and all contemporary Merriam-Webster dictionaries trace their lineage to that of Webster, although many others have adopted his name, attempting to share in the popularity.

In 1850 Blackie and Son in Glasgow published the first general dictionary of English that relied heavily upon pictorial illustrations integrated with the text. Its The Imperial Dictionary, English, Technological, and Scientific, Adapted to the Present State of Literature, Science, and Art; On the Basis of Webster’s English Dictionary used Webster’s for most of their text, adding some additional technical words that went with illustrations of machinery.