Contrary to popular belief "only sons," "the last son to carry the family name," and "sole surviving sons" must still register with the Selective Service System and they can be drafted.
IF A DRAFT WERE HELD TODAY –
These men may be entitled to a deferment during a military draft if there is a military death in the immediate family.
The Military Selective Service Act does have a provision for surviving sons. This provides that where a family member has died as a result of military service, the remaining family members should be protected insofar as possible. If a draft resumes during a war or national emergency not declared by Congress (Vietnam was such a war), a man (along with any of his living brothers) who had another brother, a sister, a father, or a mother killed or missing in action while serving in the U.S. Armed Forces, will not be drafted. There must be a military service-related death of an immediate family member for a man to receive this deferment. Simply being an “only” son in a family does not suffice.
The surviving son deferment does not apply if the war or national emergency is Congressionally declared.
It is important to keep in mind that the provisions are directly related to service-connected deaths.
The mere fact that a man is the only child or only son does not qualify him for exemption - he must be the survivor of one who died as a result of military service.
The present law provides a peacetime exemption for anyone whose parent or sibling was killed in action, died in line of duty, or died later as a result of disease or injury incurred in the line of duty while serving in the armed forces of the United States. Also included are those whose parent or sibling is in a captured or missing status as a result of service in the armed forces during any period of time. This is known as the "surviving son or brother" provision. A man does not have to be the only surviving son in order to qualify; if there are four sons in a family and one dies in the line of duty, the remaining three would qualify for surviving son or brother status under the present law.
The surviving son or brother provision is applicable only in peacetime. It does not apply in time of war or national emergency declared by the Congress.
The original law, passed in 1948, exempted the sole surviving son of a family where one or more sons or daughters died as a result of military service. No restriction existed at that time to limit the exemption to peacetime. The provision was intended to protect families which had lost a member in World War II.
In 1964, recognizing that sons of World War II veterans were reaching draft age, Congress changed the law to include the sole surviving son of a family where the father, or one or more sons or daughters, died as a result of military service. At this time the peacetime-only restriction was also added to the law.
A further change was made in 1971, expanding the exemption to any son, not necessarily the sole surviving son, of a family where the father, brother or sister died as a result of military service. This provision was recently expanded to include mothers.