The industrial revolution lead to the construction of many large breweries in England. The microscope revolutionised scientific understanding, allowed the discovery of yeast and detailed analysis of the fermentation process ( this work was predominantly carried out by Louis Pasteur). New specialised forms of yeast were cultivated, allowing the production of a range of lagers and beers.
During the 1920's prohibition in the United States virtually destroyed the US brewing industry. Even today beers' popularity in the US is dwarfed by that of lager.
In more recent times the refrigerator has allowed year-round storage and enjoyment of beer. The legalisation of home brewing in the UK in 1978 has only increased the country's love of the liquid. Most recently of all beer is trying to become more sexy and encourage a new generation to drink beer over lager.