Grand Forks grew rapidly in its early years. Growth was spurred by waves of immigrants and Americans from the eastern portion of the country, the steamboat traffic on the river, and the coming of the railroad. The St. Paul, Minneapolis, and Manitoba Railway (Great Northern Railway) reached Grand Forks in 1880 and the Northern Pacific Railway came in 1887. The first settlers of Grand Forks were farmers and working men, but merchants and professional people from Minneapolis and other cities soon populated the city. After the arrival of the railroad, old wood-frame buildings were quickly replaced with brick buildings. The Hotel Dacotah, the St. John's Block, and the Security Building - all five stories - dominated the community's skyline and were a sign of a growing city.