I would expect the maple tree to be fully leafed out by now. (7/23/13) You don't say if the tree has leaves on it or just buds. Is the tree alive? You can tell if you scrape the bark and see if it is green underneath. Do you see damage by insects or equipment?  It has been a wet year, what kind of soil do you have and is it in a low spot in your yard. 
It would help to have a picture or at least answers to my questions to enable me to answer your question

Good Evening! I checked the tree this afternoon. It is not in a low spot. There is no insect damage I could see save some ants in the soil. We have the clay soil of Delaware. I cut off a trig or two from the tree and could see no green inside. The tree had some red buds in March-April but they never became leaves. That is all I can think of to add. Anne

Anne,
Hi. No green inside doesn't sound good. You can discuss further with someone from your local County Extension Office:  planting date and how it was planted, weather experience in the last year or two, did the tree receive irrigation in the drought last summer, you can check to see if the tree has nice healthy white roots or brown, discolored roots. Did the roots ever extend out past the root ball indicating that the tree was establishing itself after planting.  Plants will go through transplant shock and will take up to a year to establish in the landscape.   I would recommend you give your local Cooperative Extension Office a call to discuss in more detail.  You can ask for the Master Gardeners or Dot Abbott, Natural Resources Agent. The Delaware Kent County Extension office phone number is<personal data hidden>.    Good luck!