http://www.poppolitics.com/articles/2003/02/28/The-Sports-Song-of-Patriotism
The national anthem shows respect.
I believe the visiting teams anthem is played first
Because the sport team is representing the nation that they are from so they play their anthem, though nations like the US will play their anthem for any sporting occasions even if they are not playing as the US but as other state/city teams I am assuming simply because they are a very patriotic nation
Visitors first, then USA..
There are no instances, providing one is safe, to ignore the National Anthem.
Australia's national anthem is Advance Australia Fair.
The Star Spangled Banner is the United States' national anthem.
following courtesy and protocol visiting country has their anthem first, much like any flag raising ceremony, all other flags raise before with U.S. flag being raised last , and tallest, no anthem or flag should be raised , played after the U.S.'s
Scotland's official National Anthem is the same as the rest of the UK - 'God Save the Queen'.
The anthem of the home team is sung second. If a US team is hosting a game, the Canadian national anthem is sung first, followed by the American anthem, and vice versa.
The country from which the Gold Medal winning entity (individual, pairs, teams, etc.) represents is honored by playing their national anthem.
1875
The Philippine national anthem serves the same purpose and respect as all other national anthems. It is played before things like sporting events, or school.