If you are over 60 years old and were married at the time of his death, you can qualify for widow's benefits if either of the following is true: 1) you were married for at least 9 months; or 2) you had children together. If either of these is true, and if he was fully insured for Social Security, you should be eligible to recover. There are some exceptions to this, such as if you are remarried or if you are receiving a retirement benefit that is larger than his benefit.
If you are between the ages of 50 and 60, you will be eligible for his benefits if you are disabled.
If you think you qualify for widow's benefits, go to your local social security office and complete an application for widow's insurance benefits. If you are lacking in any of the eligibility requirements, they will let you know.