CREATE TABLE table_77428 ("Year" FLOAT, "Player" TEXT, "Position" TEXT, "Nationality" TEXT, "Team" TEXT)

What's the position when the player was Justin Mapp Category:articles with hcards with a United States nationality?
SELECT "Position" FROM table_77428 WHERE "Nationality" = 'united states' AND "Player" = 'justin mapp category:articles with hcards'
SELECT "Position" FROM "table_77428" WHERE "Nationality" = 'united states' AND "Player" = 'justin mapp category:articles with hcards'