The city grew rapidly throughout the first half of the 19th century, serving as an entry point and more often than not eventual home for millions of foreign immigrants. It quickly became a bustling metropolis that served not only as a financial center but also a leader in the fields of manufacturing and industry. It remained unscathed during the first American Civil War (although thousands of its denizens died fighting in the conflict) and, along with other Northern cities, ended up swelling with black refugees from the Confederacy. More European immigrants arrived throughout the second half of the century and New York was by far the largest city in the United States by the time the five boroughs were consolidated into a single city in 1898.