We usually see portraits of slavery in the United States during the 19th Century in movies and books, but how was slavery in the United Kingdom, France and Germany? Did they treat slaves the same way Americans did?
What gave you the idea there was slavery in western Europe?
Slavery was illegal in England. It was found to be so in a number of famous court cases.
The first case was "Smith v Gould" in 1701. Sir John Holt, Lord Chief Justice of England ruled, "No man can have property in another. There is no such thing as a slave by the law of England."
In 1705 in "Smith v Brown and Cooper", Chief Justice Holt re-iterated the same ruling, "As soon as a Negro comes into England he becomes free. One may be a villein in England, but not a slave".
Obviously, there were still some slave owners who brought their slaves into England and tried to get away with it, because there were several other famous court cases: In 1762, in "Shanley v Harvey", Lord Henley ruled, "As soon as a man sets foot on English ground, he is free." In 1772 "Somersett's Case" again held that the condition of slavery did not exist under English law, and that slaves who arrived in England or Wales were free.
Slavery obviously was legal in many parts of the British Colonies. Britain banned the slave trade in 1807, and abolished slavery throughout the British Empire in 1833.
Source: http://www.anti-slaverysociety.addr.com/huk-slavery.htm