Comparing FMA manga to the animes Which came out first Fullmetal Alchemist the manga, Fullmetal Alchemist the anime or Fullmetal Alchemist Brotherhood?
2001 to 2010 - the manga is published.
Fall 2003 to Fall 2004 - the first anime is aired.
Spring 2009 to Summer 2010 - the second anime (Brotherhood) is aired. 


As you can see, the ending of the manga was timed to coincide with the end of Brotherhood.