Portland had a rapid growth of population and increase in wealth during the European disturbances caused by the ambition of Napoleon. The carrying-trade of the world was almost monopolized by neutral American bottoms, and ship-building became then, as it continued to be for a long time afterward, a leading industry along the Maine coast. Great fortunes were made by Portland ship-owners. Many fine old-fashioned mansions that now ornament Congress, High, State, Spring, and Danforth Streets, were built by merchants in the first years of the present century, and are [Illustration: FIRST PARISH CHURCH. CONTAINING THE MOWATT CANNON-BALL.] reminders of the peculiar conditions of that time. A sharp check to the rising tide of prosperity was given by the embargo act of 1807. After the peace of 1815, the trade with the West Indies grew into great importance, and for fifty years was a leading factor in the commerce of Portland. Lumber and fish were the chief exports, and return cargoes of sugar and molasses made this the principal market for those commodities--the imports in these lines for many years exceeding those at New York and Boston. West India molasses was distilled in large quantities into New England rum, until the temperance reform, under the lead of the Portland philanthropist, Neal Dow, closed up the distilleries; in their place came sugar factories and refineries which turned out a more wholesome product. But about thirty years ago, changes in the methods of making sugar caused the loss of this industry to Portland. The development of the canning business has of late years been an important feature of the industrial prosperity of Maine, owing partly to the fact that the climate and soil of this State produce a quality of sweet corn that cannot be matched in other States, and also to the fact that the system of canning now in use was a Portland invention. All over the interior of Maine may be found corn factories owned by Portland merchants, and, on the coast, canneries of lobsters and other products of the fields and fisheries of Maine.