At a press conference in Chicago, Obama announced his nominations of former Iowa governor Tom Vilsack as the agriculture secretary and Colorado Senator Ken Salazar as the secretary of interior.  

"Together they will serve as guardians of the American landscape on which the health of our economy and the wellbeing of our families so heavily depends," Obama told reporters.

"Ken will bring to the Department of the Interior an abiding commitment to this land we love," Obama said of his Interior Secretary choice. "His family has farmed and ranched the same land in Colorado for five generations. As a Senator from the great state of Colorado, he has been a champion for farmers, ranchers, and rural communities."

Born on March 2 to a rancher family in Colorado, Salazar graduated from the University of Michigan with a law degree.

He was elected as the Colorado Attorney General in 1998 and won the reelection four years later, "where he worked on a number of land, water, and environmental issues." In 2005, he took office in the Senate.

Salazar told the press conference that as the nominee to be secretary of the interior, he would do all to help reduce America's dependence on foreign oil, build clean energy economy, protect national lands and work to confront water supply challenges.

Vilsack was an adopted orphan from Puttsburgh, Pennsylvania and graduate from Albany Law School. After marrying his wife, Ann Christine Bell, he moved to her hometown in Iowa.

Vilsack was elected mayor of Mount Pleasant in 1987 and won a seat in the state Senate five years later. In 1998, he won the governorship, making it the first time in 30 years that a Democrat was elected the state governor.

"As our next Secretary of Agriculture, Tom will help ensure that rural America has a true partner in implementing the Farm Bill and pursuing agricultural research," said Obama.

He becomes the fourth former Democratic challenger for the 2008presidential nomination to join Obama's administration following Joe Biden, Hillary Rodham Clinton and Bill Richardson.

Vilsack quickly dropped out of the Democratic race because he had trouble raising money. He endorsed Clinton and campaigned for her.

"I look forward to working with congressional leaders who share the president-elect's vision of bringing hope to rural America, of being good stewards of our natural resources, are providing American leadership on climate change and making America a nation truly dedicated to health and nutrition," he told reporters.

To fill his cabinet, Obama is expected to name secretaries of Labor and Transportation departments. He will also choose leaders for the intelligence agencies and a trade representative.