Possible Clues:

• Some D.C. pros
• Country folk, as no Latin may be?
• Current cricket side welcomed by old province's citizens
• Races with a grandstand finish!
• Grand races, no doubt
• Stan, a lion (anag.)
• Poles welcoming displaced Laotian and countrymen
• Angle article brought up about Italy and old people born locally?
• Beltway Series team
• D.C. baseball players ... or what the ends of 17-, 21-, 39- and 55-Across sound like