"Public service was her calling, and there was no job she loved more than representing the people of Contra Costa, Alameda and Solano counties," her family said.
Tauscher left Congress in 2009 during her seventh term, when President Barack Obama appointed her to a position with the State Department, where she served as the under secretary of state for arms control and international security under then-Secretary of State Hillary Clinton.
In that role, Tauscher helped lead negotiations with Russia over the 2010 New START treaty, which limits each country to no more than 1,550 deployed nuclear warheads and 700 deployed missiles and bombers.
"She made America and the world safer through her work on arms control at the State Department," Clinton said in a statement. "Ellen woke up every day determined to make a difference, and make a difference she did."