It all started when the Chinese mixed some herbs together and created a very nice tasting concoction of pickled fish and spices. By early 1700s, the table sauce, which was immensely popular in China gained fame elsewhere like in Malaysia. That is where it was discovered by the western civilization, England. The English fell in love with this sauce, in 1740s. It spread from there on like the Spanish flu but it wasn’t lethal like that disease. One of the places it spread to was, at the time one of the British Colonies. The 12 colonies, the United States, the inhabitants there mixed it with some tomatoes and till this day they have been like that ever since.
Others never thought of it because for most of the 18th century and before, Tomatoes were thought to be poisonous like their relatives Belladona and nightshade plants. But when the sauce made it to the colonies new discoveries favored the Tomatoes true nature, a safe healthy fruit.