Victor Espinoza rides American Pharoah to victory in the 141st running of the Kentucky Derby on Saturday, May 2, 2015, in Louisville, Ky. (AP Photo/Morry Gash)
Victor Espinoza rides American Pharoah to victory in the 141st running of the Kentucky Derby on Saturday, May 2, 2015, in Louisville, Ky. (AP Photo/Morry Gash)
Victor Espinoza rides American Pharoah to victory in the 141st running of the Kentucky Derby on Saturday, May 2, 2015, in Louisville, Ky. (AP Photo/Morry Gash)
Victor Espinoza rides American Pharoah to victory in the 141st running of the Kentucky Derby on Saturday, May 2, 2015, in Louisville, Ky. (AP Photo/Morry Gash)
Victor Espinoza rides American Pharoah to victory in the 141st running of the Kentucky Derby on Saturday, May 2, 2015, in Louisville, Ky. (AP Photo/Morry Gash)
The scene at the Kentucky Derby on Saturday, May 2nd, 2015 (Photo/Charlie Riedel)
The scene at the Kentucky Derby on Saturday, May 2nd, 2015 (Photo/Charlie Riedel)
The scene at the Kentucky Derby on Saturday, May 2nd, 2015 (Photo/Charlie Riedel)
The scene at the Kentucky Derby on Saturday, May 2nd, 2015 (Photo/Charlie Riedel)
The scene at the Kentucky Derby on Saturday, May 2nd, 2015 (Photo/Charlie Riedel)
The scene at the Kentucky Derby on Saturday, May 2nd, 2015 (Photo/Matt Slocum)
The scene at the Kentucky Derby on Saturday, May 2nd, 2015 (Photo/Brynn Anderson)
The scene at the Kentucky Derby on Saturday, May 2nd, 2015 (Photo/Charlie Riedel)
The scene at the Kentucky Derby on Saturday, May 2nd, 2015 (Photo/Charlie Riedel)
The scene at the Kentucky Derby on Saturday, May 2nd, 2015 (Photo/Jeff Roberson)
The scene at the Kentucky Derby on Saturday, May 2nd, 2015 (Photo/David J. Phillip)
The scene at the Kentucky Derby on Saturday, May 2nd, 2015 (Photo/Brynn Anderson)
The scene at the Kentucky Derby on Saturday, May 2nd, 2015 (Photo/Matt Slocum)
The scene at the Kentucky Derby on Saturday, May 2nd, 2015 (Photo/David J. Phillip)
The scene at the Kentucky Derby on Saturday, May 2nd, 2015 (Photo/Matt Slocum)
The scene at the Kentucky Derby on Saturday, May 2nd, 2015 (Photo/Matt Slocum)
A horse gets a bath after a morning workout at Churchill Downs on May 1, 2015, in Louisville, Ky. (AP Photo/Charlie Riedel)
A woman wears a hat before the 141st running of the Kentucky Derby horse race at Churchill Downs on May 2, 2015, in Louisville, Ky. (AP Photo/Brynn Anderson)
Ginny Keen wears a hat before the 141st running of the Kentucky Derby horse race at Churchill Downs on May 2, 2015, in Louisville, Ky. (AP Photo/Brynn Anderson)
Michael Parrett, left, and Dustin Doerflinger look over their bets before the 141st running of the Kentucky Derby horse race at Churchill Downs on May 2, 2015, in Louisville, Ky. (AP Photo/Charlie Riedel)
Lovely Maria, ridden by Kerwin Clark, wins the Longines Kentucky Oaks on May 1, 2015, in Louisville, Ky. (Photo by Diane Bondareff/Invision for Longines/AP Images)
Exercise rider Patti Krotenko gallops Kentucky Derby entrant Carpe Diem at Churchill Downs in Louisville, Ky. on May 1, 2015. (AP Photo/Garry Jones)
A woman wears a hat during a morning workout for the 141th running of the Kentucky Derby horse race at Churchill Downs on May 1, 2015, in Louisville, Ky. (AP Photo/Darron Cummings)
Horses are seen in their stalls after a morning workout at Churchill Downs on May 1, 2015, in Louisville, Ky. (AP Photo/Jeff Roberson)
A horse is walked after a morning workout at Churchill Downs on May 1, 2015, in Louisville, Ky. (AP Photo/Darron Cummings)
Kentucky Derby favorite American Pharoah, ridden by exercise rider Jorge Alvarez, gallops at Churchill Downs in Louisville, Ky. on April 30, 2015. (AP Photo/Garry Jones)
Exercise rider Vicki King takes Kentucky Derby entrant Upstart for a morning workout for the 141th running of the Kentucky Derby horse race at Churchill Downs on May 1, 2015. (AP Photo/Charlie Riedel)
A horse is taken out for a morning workout at Churchill Downs on May 1, 2015, in Louisville, Ky. (AP Photo/Darron Cummings)
LOUISVILLE, Ky. -- The 141st Kentucky Derby returns to Churchill Downs on Saturday. Check out all the celebrities, wild hats, and of course the horses at what is known as "the most exciting two minutes in sports."