The colony that had the most to gain from joining Confederation was likely the Province of Canada (consisting of present-day Ontario and Quebec). Confederation provided the Province of Canada with a larger market for its goods, increased political stability, and access to the resources of the other colonies. Confederation also helped to address some of the political and economic difficulties that the Province of Canada was facing, such as tensions between French and English-speaking citizens.
The colony that had the most to lose from joining Confederation was likely Nova Scotia. Nova Scotia was a leading shipbuilding and fishing center, and joining Confederation meant losing its independence and being subjected to tariffs and regulations that were not in its best interest. Some Nova Scotians also feared that Confederation would lead to the loss of their traditional ways of life and control over their local resources.