Lac Saint-Pierre is a lake in Quebec, a widening of the Saint Lawrence between Sorel-Tracy and Trois-Rivières. Its shallow depth imposed limits on the tonnage of boats crossing it and strong winds there caused many shipwrecks. The route of the waterway developed at this location has followed, since the 1850s, the natural route of a deeper trench which curves towards the north at the mouth of the Sorel islands. The channel was deepened and widened by dredging work after 1851. The first dredging work was meant to replace the natural channel, considered too crooked, with an artificial channel which would be straight and more direct. In these documents from the Legislative Assembly of Canada, various engineers and officials discuss the measures and funds required to dig the channel. Killaly was a civil engineer and political figure in early Canada. Other correspondence from Thomas A. Begly, James State, E. C. Casgrain, etc.
