I concur with In-Silico. 'to know' in English has two main meanings : 'to have knowledge of sth.' and 'to be aquainted with so./sth.'. 'I know all about the Civil War' would translate to 'Ich weiß alles über den (amerikanischen) Bürgerkrieg' while you would use 'Ich kenne Peter' or 'Ich kenne das Buch' for 'I know Peter' or 'I know the book', respectively. Be careful: In German 'Ich kenne das Buch' can also be said if you just know about its existence ('I've heard about the book') or have read it superficially. So its meaning is somewhat weaker than the English 'I know the book'.

Wissen is knowing as in knowledge. Kennen is knowing as in being acquainted with.

Another way to put that is Wissen is Knowledge but Kennen is understanding

Wissen is used to say someone knows something and kennen is used to say someone knows someone.