The passage of the Kansas- Nebraska Act
Maybe they think its the right thing to do???
The Industrial Revolution and new jobs in factories contributed to growth of cities in the late 1800's, as did immigration.
Answer: Effusive eruptions occur when hot, (12000C) runny basalt magma reach the surface. Dissolved gases escape easily as the magma erupts, forming lava that flows downhill quite easily. Effusive eruptions build up gently-sloping Shield Volcanoes like Hawaii.
Explanation: