The whole thing literally split in two. The good news for me is, I learned right away, on that first project, and the wood was free. Without going into the details of why wood moves in the directions it does, I'd like to just present the facts and some methods to account for wood movement in various projects. This of course will not be a complete list, and if you would like to send me your ideas, I can add them to this article and let it grow. I am still learning.
Wood expands and contracts across the grain significantly more than lengthwise with the grain.
When joining boards with the grain running at 90 angles to each other, never glue rigidly all the way across the grain. As the wood expands or contracts it will weaken or break the bond or if the glue holds, it could split the wood. Wood of the same species can always be rigidly joined when their grain runs in the same direction. To attach the two together, use a mechanical fastener, such as a screw, with an elongated hole, which will allow the wood underneath to move. For a dresser or desktop, you would rigidly affix at the front to maintain the front of the piece's dimensions allowing the wood to grow toward the back, where the growth or shrink will not be seen.