After reading about Common-Law, you're probably wondering why you'd even be interested in getting a Federal Trademark for your name. Well, let's break down the key reasons as provided by the USPTO.
1) Constructive notice nationwide of the trademark owner's claim
Essentially, this means that no other party will have the right to use the same or confusingly similar name throughout the US. It also means you can use the ® symbol.
2) Evidence of ownership of the trademark
The records of the USPTO are public and therefore, it'll be obvious you own the Federal trademark.
3) Jurisdiction of federal courts may be invoked
Should another party infringe on your Federal trademark rights, you'll be able to use the Federal court system.
4) Registration can be used as a basis for obtaining registration in foreign countries
If you do want to extend outside of the US, you'll be able to use your US Federal trademark registration as a claim for priority.
5) Registration may be filed with U.S. Customs Service to prevent importation of infringing foreign goods
You'll be able to record your Federal trademark with U.S. Customs & Border Protection to prevent the importation of goods that infringe upon your mark. Read more here.
All of the above advantages are yours once you obtain a Federal trademark. However, all of the above can only be yours once you know that the mark is truly available AND the application has been completed correctly.