In 1998, she made her international debut for the United States against Argentina, with Sobrero on the back of her jersey. She switched to Markgraf on the back of her jersey in 2004. She was the least experienced starter in the winning 1999 World Cup team and one of the youngest members of the team. The LA Times selected her to the All-World top 11 for her play at centerback that tournament. She started in the 2000 Olympic Games in Sydney, the 2004 Games in Athens, and was Co-Captain for the 2008 Games in Beijing. She won the silver medal in 2000, the gold in 2004, and the gold in 2008. She played 12 matches in 3 FIFA Women's World Cup, winning the title of World Champion in the 1999 World Cup hosted by the US. She was also a member of the teams that finished third in the 2003 World Cup hosted by the US and the 2007 World Cup hosted by China.