Why did they use steamships?

Answer 1

They came in common use after several developments that improved the steam engine and power transer. A major innovater was James Watt! The screw propeller was key for ocean going vessels. Paddle wheels are inefficient and expose their working parts to the weather. The screw propeller is submerged and less prone to damage as long as it has clearance underwater. Coal was a common item for import export so there was a supply at many ports. The crews were smaller. Sails on large ships are labor intensive.

Faster better cheaper!

OTOH, steam ships were used to get people and stuff from place to place. :-)

Wikpedia has a good article.

Answer 2

Steamships were used primarily because they were faster and more reliable than sailboats, allowing for quicker transportation of goods and people across long distances. They were also less dependent on wind conditions, making them more efficient for regular schedules. Additionally, steamships could carry heavier cargo loads, making them more cost-effective for trade and commerce.