Jenny Sanford: I Learned Of Affair In Jan.

South Carolina first lady Jenny Sanford says she discovered her husband's affair in January when she found a letter to the governor from his mistress.

Jenny Sanford told The Associated Press on Friday she told him to end the affair and was shocked this week when she found out he'd gone to Argentina to see his mistress. She says she believed Gov. Mark Sanford had gone somewhere to work on writing a book.

Jenny Sanford says she stayed with her husband while their four sons were attending their private school in Columbia. She waited until the school year ended to leave him for their coastal home on Sullivans Island.

She wept as she displayed her boys' stellar report cards and said she most worries about how they're being affected by the scandal. Jenny Sanford says she plans to take them out of the state for the weekend.

Meanwhile, Sanford was back at work today, telling his state agency chiefs that he's sorry for keeping them in the dark when he went to see Argentina to see his mistress.

The Republican on Friday held his typical public meeting with the agency chiefs, but started with apologies and likening his confession and future to the biblical plight of King David.

Sanford says King David fell mightily but picked up the pieces and built from there.

Sanford made specific apologizes to the head of agencies that handle his security and economic development trips, saying he put those leaders in awkward spots.

He dismissed his security detail before flying to Argentina last week and he also took a trip with Commerce Department officials to South America and saw his mistress.