When John Jameson acquired the Bow Street Distillery in 1780, it was producing about 30,000 gallons annually. By the turn of the 19th century, it was the second largest producer in Ireland and one of the largest in the world, producing 1,000,000 gallons annually. Dublin at the time was the centre of world whiskey production. It was the second most popular spirit in the world after rum and internationally Jameson had by 1805 become the world's number one whiskey. Today, Jameson is the world's third largest single-distillery whiskey.
Historical events, for a time, set the company back. The temperance movement in Ireland had an enormous impact domestically but the two key events that affected Jameson were the Irish War of Independence and subsequent trade war with the British which denied Jameson the export markets of the Commonwealth, and shortly thereafter, the introduction of prohibition in the United States. While Scottish brands could easily slip across the Canadian border, Jameson was excluded from its biggest market for many years.
The introduction of column stills by the Scottish blenders in the mid-19th-century enabled increased production that the Irish, still making single pot still whiskey, could not compete with. There was a legal enquiry somewhere in 1908 to deal with the trade definition of whiskey. The Scottish producers won within some jurisdictions, and blends became recognised in the law of that jurisdiction as whiskey. The Irish in general, and Jameson in particular, continued with the traditional pot still production process for many years.
In 1966 John Jameson merged with Cork Distillers and John Powers to form the Irish Distillers Group. The New Midleton Distillery built by Irish Distillers produces most of the Irish whiskey sold in Ireland.-Wikipedia