Call it the Arc de Trump. President Trump posted an architect’s rendering of a huge triumphal arch to mark the nation’s 250th birthday – and his biggest change yet to the capital’s skyline. The stone arch would be constructed just across the Potomac River from the Lincoln Memorial — soaring above that memorial’s 99-foot height — and add a major new element to DC’s public architecture. The online sketch depicts a massive monument that bears a strong resemblance to the Washington Square Park arch in Manhattan and the Arc de Triomphe in Paris. The stone monument features carved wreaths, two...