In 1853, upon completion of the Grand Trunk Railway to Montreal, Portland became the primary ice-free winter seaport for Canadian exports. The Portland Company, located on Fore Street, manufactured more than 600 19th-century steam locomotives, as well as engines for trains and boats, fire engines and other railroad transportation equipment. The Portland Company was, for a time, the city's largest employer and many of its employees were immigrants from Canada, Ireland and Italy. Portland became a 20th-century rail hub as five additional rail lines merged into Portland Terminal Company in 1911. Following nationalization of the Grand Trunk system in 1923, Canadian export traffic was diverted from Portland to Halifax, Nova Scotia, resulting in marked local economic decline. In the 20th century, icebreakers later enabled ships to reach Montreal in winter, drastically reducing Portland's role as a winter port for Canada.