Mathew Carey was an Irish printer, pamphleteer, and editor; his Volunteers Journal became the second largest journal circulating through Ireland. He was already a bit of a rabble-rouser when he published a controversial cartoon in April 1784. In the image, the Chairman of the Irish Parliament's Committee of Ways and Means was hanging from as noose as a traitor. Carey's arrest was soon ordered. The libel case still pending when he fled for Philadelphia (shortly after meeting Benjamin Franklin) on September 7, 1784 aboard the ship America. He was smuggled on board dressed as a woman. As Carey himself later wrote in his autobiography: "I got on board in female dress, and must have cut a very gawky figure."
He arrived two months later. Around the same time, his old friend the Marquis de Lafayette happened to be in town and the two visited. Carey mentioned his ambition to start a newspaper in Philadelphia. Lafayette gave him $400 and wrote a letter of endorsement to George Washington. The inaugural issue of the Pennsylvania Evening Herald was published less than three months later. After some success, Carey had bigger plans and soon launched Columbian Magazine, the first national magazine in the United States. After some difficulty with his partners, he started his own rival publication, The American Museum.
Facing low profits, Carey started his own bookstore and imported books from Europe, particularly his native Ireland. His store soon become one of the largest in the country. The book store soon became a publishing house with the help of Mason Locke Weems, who served as a traveling salesman. The partnership proved instantly successful. One of their most popular books was America's first Roman Catholic Bible, often referred to as the Carey Bible.
Mathew Carey retired in 1825, leaving his business to his son Henry C. Carey; Henry soon partnered with Isaac Lea. The publishing house of Carey and Lea (and its various incarnations) became a huge force and turned the city of Philadelphia into a major hub of the book industry for a time.
*Much of the information in this post can be found in Mathew Carey, Publisher and Patriot by James Green.