John Jameson & Son was the second largest distilling company in Ireland by the early part of the 19th century. News about the quality of the Jameson whiskeys travelled far and wide and demand was growing not just at home but abroad. The combination of fine whiskey ingredients and superior distilling processes was making quite a name for Jameson whiskeys worldwide. In 1858, a blight destroyed France's vineyards and supplies of brandy dried up. Traditional brandy drinkers switched to Irish whiskey, and Jameson sales soared.
By 1890, Ireland had about 90% of the global whiskey export market and the Jameson distillery was making 10% of Ireland's annual whiskey output. In the early part of the 20th century Jameson Whiskey was dealt two cruel blows. Jameson was a best selling whiskey in America. But after Prohibition in 1919, exports of Jameson to the USA ground to a halt. Jameson had also been the most popular whiskey in the British Empire. After Irish Independence however, English tariff barriers priced it out of the market. Without overseas demand, all 400 Irish whiskey brands fell into decline. The future looked bleak for John Jameson & Son and the Irish distillery market