In 1857, at the age of 19, Neal settled in San Francisco. He was hired as a draughtsman on wood by a friendly wood-engraver, who took an interest in him, and taught him the art. Soon after, he became the city's best ink drawer upon blocks used by engravers. In fact, his sketching ability was so good that he was hired, from time to time, by the police for likenesses of criminals for the Rogue's Gallery. The first exhibit of his work was at the San Francisco Mechanics' Institute in 1857, and his second was at the 1859 California State Fair. After two years he earned enough money to return to New England for a short while to take art classes at the Andover Academy, but returned to San Francisco when his money ran out. Once back, Neal quickly established himself as one of the city's best portrait artists. He painted portraits of Rev. Mark Hopkins, millionaire Ogden Mills, Judge Hoffman, and Mayor Adolph Sutro, to name a few. While living in California, Neal became friends with Bret Harte and Charles Christian Nahl, with whom he learned many of his early painting techniques.