Why did Spain and Portugal become poor in the 1800's?

Answer 1

For Portugal, the cause was the occupation by Napoleon. The royal Family and a great part of Portugal's economic and social élite fled to its colony Brazil that already was prosperous and that with the arrival of King and nobles became the center of the Portuguese Empire and the focus of economic development. Portugal itself became much of a backwater, already having suffered the results of wars and earthquakes since the 1750's.

When the King returned in 1821 and tried to reverse Brazil's status back to 'colony', his son - who he had left there to rule in his stead - put himself at the head of the movement that declared Brazil independent. The loss of its richest posession caused Portugal to become poor and remain so for well over a hundred years

Spain's case was slightly different. The steady flow of silver from its American posessions since the 16th century had caused Spain to neglect its own economic development while at the same time spending its silver on being a big player in European politics, spending huge amounts on wars that seldom came out profitable. When the flow finally dried up, Spain basically was a banana republic that had run out of bananas. On top of that came Napoleon's conquest of Spain, followed by decades of civil unrest and civil war. At the same time, Spain's colonies started clamoring for independence and in the course of the 19th century Spain lost practically all of them.

Answer 2

They elected a bad prime minister who cut off all trade making the country poor