This Colossal Project presents an absorbing epic on the building of the fourth Welland Canal, which connects Lake Ontario and Lake Erie and allows ships to bypass Niagara Falls. An immense undertaking, the canal is a vital part of North America's infrastructure and still functions as an essential part of the St Lawrence Seaway. Emphasizing the role that vivid personalities – including engineers John Laing Weller and Alex Grant as well as contractors and labourers – played in the construction of the canal, Roberta Styran and Robert Taylor use archival sources, government documents, newspapers, maps, and original plans to describe a saga of technological, financial, geographical, and social obstacles met and overcome in an accomplishment akin to the building of the Canadian Pacific Railway. A story of Canadian skill, courage, vision, and hardship, This Colossal Project details the twenty-year excavation of the giant channel and the creation of huge concrete locks amidst war, the Great Depression, political change, and labour unrest. Building on the work presented in Styran and Taylor's This Great National Object, which told the story of the first three Welland canals built in the nineteenth century, This Colossal Project chronicles an impressive milestone in the history of Canadian technological achievement and nation building.