Some simplifications were made by Noah Webster.
Webster thought that Americans should learn from American books, so he began writing a three volume compendium, A Grammatical Institute of the English Language. The work consisted of a speller (published in 1783), a grammar (published in 1784), and a reader (published in 1785). His goal was to provide a uniquely American approach to training children. His most important improvement, he claimed, was to rescue "our native tongue" from "the clamour of pedantry" that surrounded English grammar and pronunciation. He complained that the English language had been corrupted by the British aristocracy, which set its own standard for proper spelling and pronunciation. Webster rejected the notion that the study of Greek and Latin must precede the study of English grammar. The appropriate standard for the American language, argued Webster, was "the same republican principles as American civil and ecclesiastical constitutions". This meant that the people-at-large must control the language; popular sovereignty in government must be accompanied by popular usage in language.
Slowly, edition by edition, Webster changed the spelling of words, making them "Americanized". He chose s over c in words like defense, he changed the re to er in words like center, and he dropped one of the Ls in traveler. At first he kept the u in words like colour or favour but dropped it in later editions. He also changed "tongue" to "tung"—an innovation that never caught on.
https://en.wikipedia.org/wiki/Noah_Webster