Are you a Tolkien scholar?Gandalf first met up with Bilbo in 2941 T.A. In 2989, Balin lead the dwarves to try and reclaim Moria. It was successful at first, killing a ton of orcs but they were finally defeated by the orcs again in 2994. So it was around 48 years after the events of the Hobbit that the Balin campaign began. Welcome to TTF!
Definitely not a scholar, just an avid fan. We do have quite a few members who are much more knowledgeable than me. LOTR and The Hobbit come from the Red Book of Westmarch, which was written by Bilbo and later Frodo.