Ключевые слова: america, background, barricade, barrier, border, boundary, concept, crossing, customs, defense, department, desert, dirt, emigration, fence, flag, forbidden, government, homeland, illegal, immigrant, immigration, international, limit, mexican, mexico, migration, national, patrol, protect, protection, protectionism, road, security, separation, smuggling, states, stop, surveillance, trail, travel, united, usa, wall, war,