'Bridges of Madison County' Author Dead at 77

Robert James Waller, best known for penning the romantic novel "The Bridges of Madison County," has died.

Waller passed away in Texas either Thursday or Friday, according to his literary agency after battling some sort of illness.

Waller wrote several books but "Bridges of Madison County" was his most popular, spending over 3 years on the New York Times bestseller list. Rumor has it he wrote the book -- about a National Geographic photographer who falls in love with a married Italian woman while on assignment in Iowa -- in only 11 days.

The novel was later turned into a Clint Eastwood-directed film starring Meryl Streep that grossed millions and earned Meryl her 10th Oscar nom.

Some of other Waller's notable works include "Puerto Vallarta Squeeze", 'A Thousand Country Roads' and "Slow Waltz in Cedar Bend."