Object Alignment

Dear Blender Community,

 Recently, I have been starting to work in Unity, making simple 3D games.  I have wanted to add a building to my game, however, I want it to look as nice as possible.  So I have been having trouble trying to find out how to align two objects perfectly.  I'm simply taking two identical walls (just cubes that have been scaled) and trying to align their corners.  Any help is much obliged.  Thank you!

Sincerely, KetoBlends

I found a fix. Just hold Ctrl+Shift+Tab, select Verticies, hit G, and move your mouse over the vertex you want to snap to.