ANSWERS:
A1. This is a little bit of a tricky one! New Yorker George Hincapie of the US Postal Team came 2nd in 2005 but that result became void due to his doping admission. That leaves three 4th place results: a pair of 4th place finishes in both 1999 and 2001 by Big George as well as a 4th place finish by American pioneer Greg Lemond back in 1985 as the best American results.
A2. Frenchman Bernard Hinault had also won two Tours de France when he triumphed in the 1981 Paris-Roubaix, while wearing the Rainbow bands of World Champion, no less! As for Flanders, you would have to go back to 1975 and a certain Belgian named Eddy Merckx! In the modern era, Classics and Grand Tours have really become the domain of specialists and Pogačar is an exciting throw-back to the Merckx/Hinault era of strong all-around riders that performed on all terrains throughout the year. I, for one, hope he can join them!
A3. Liège-Bastogne-Liège, which Adri van der Poel won in 1988. Most experts think this race is too hilly for Mathieu, but given his talent and current form, I would not bet against him!
A4. The Flèche Wallonne in Belgium, won by Lance Armstrong in 1996. Many of Lance’s results were negated due his doping admissions but is one of the few that remains.
A5. Greg Lemond, 2nd in 1986 behind Irishman Sean Kelly and Fred Rodriguez, 2nd in 2002 behind Italian Mario Cipollini.
Coryn Rivera became the first-ever American to win the Tour of Flanders in 2017.