From press release from Washington International Horse Show

The best horses and riders from around the world will soon meet on the streets of the U.S. capital for the Washington International Horse Show (WIHS), presented by MARS EQUESTRIAN™, from October 22 through 27, 2019, at Capital One Arena in Washington, D.C.

Seven nations have qualified to make up the WIHS international roster, including Australia, Belgium, Canada, Great Britain, Ireland, and Switzerland. Representing their country on home soil, the U.S. rider list is stacked with the likes of Olympians Kent Farrington, Laura Kraut, and McLain Ward, as well as defending President’s Cup champion Beezie Madden.

WIHS will continue a longstanding tradition as one of the world’s most celebrated indoor horse shows in 2019 and again host the $136,300 Longines FEI Jumping World Cup™ Washington, presented by Events DC for the Presdient's Cup, with coveted qualifying points on offer for the 2020 Longines FEI Jumping World CupTM Final taking place in Las Vegas, NV, in April.

International Riders qualified to compete at the 2019 WIHS:
(As of Wednesday, October 2)

Bertram Allen (IRL)
Molly Ashe Cawley (USA)
Erynn Ballard (CAN)
Georgina Bloomberg (USA)
Brian Cournane (IRL)
Jordan Coyle (IRL)
Amanda Derbyshire (GBR)
Katherine Dinan (USA)
Kent Farrington (USA)
Margie Engle (USA)
Alex Granato (USA)
Cormac Hanley (IRL)
Leslie Howard (USA)
Darragh Kenny (IRL)
Andrew Kocher (USA)
Laura Kraut (USA)
Peter Lutz (USA)
Elizabeth "Beezie" Madden (USA)
Beat Mändli (SUI)
Brian Moggre (USA)
Michael Pender (IRL)
Devin Ryan (USA)
Adrienne Sternlicht (USA)
Shane Sweetnam (IRL)
Catherine Tyree (USA)
Aaron Vale (USA)
Kristen Vanderveen (USA)
Jos Verlooy (BEL)
McLain Ward (USA)
Andrew Welles (USA)
Rowan Willis (AUS)