Christie's has announced that it will be responsible for the sale of artworks from the collection of Senator Frank R Lautenberg (1924-2013) in a series of auctions, with Edward Ruscha's Untitled 1985 the most highly valued.

The sales will take place over Autumn 2013 and Spring 2014, with Lautenberg's collection appearing in November 6's Impressionist and Modern Art sale, the November 12-13 Post-War and Contemporary Art auction, and Photographs in April 2014.

Edward Ruscha's Untitled, 1985, a "cinematically scaled canvas" depicting the American flag, is the highlight of the collection, estimated at $1.5m-2.5m. An oil on canvas, it will be sold as part of the Post-War and Contemporary Art sale.

Lautenberg was a five-term senator of New Jersey. His collection includes some of the top names in post-war and contemporary art, including Jasper Johns, Robert Rauschenberg, Edward Ruscha, Cindy Sherman and Andy Warhol.

Further highlights include Robert Rauschenberg's Untitled, 1965, a collage that was commissioned by the Congress of Racial Equality and celebrates civil rights legislation.

Filled with iconic images, it includes a portrait of John F Kennedy, a Native American figure, Liberty and a civil war monument. It is valued at $300,000-500,000.

Jasper John's Flags 1 will also be sold, with an estimate of $250,000-350,000. It is described by Christie's as "the definitive masterpiece of Jasper Johns' prolific career as a printmaker."

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