Chickadee Nests in My First Bird House

I recently bought my first bird house from Texas Arts and Crafts. The bird house is the Texas State Bird House. I did research on where to place it and what birds it might attract. My results were to place it eight to twenty feet up, and I would attract one of these birds American Kestrel, the Great Crested Flycatcher, Wrens, Chickadees, Nuthatches, Titmice, Swallows, or Woodpeckers. We placed it approximately eight feet up in my pecan tree in my front yard. I find it hard to believe that I found a Chickadee nesting in my bird house thirty six hours after we hung it. I thought it would at least take more time (if at all).