Championing American Business Through Diplomacy Act of 2019 This bill establishes within the Department of State an Assistant Secretary of State for Economic and Business Matters, and establishes that a principal duty of a diplomatic mission to a foreign country is the promotion of U.S. economic and commercial interests in that country. The Assistant Secretary shall be responsible for matters relating to international economics and business matters in foreign policy. The State Department shall train various Foreign Service officers, as part of their standard training, on matters including economic and commercial diplomacy, with a particular focus on market access, commercial advocacy, and increasing awareness of U.S. government assistance available to businesses. The President shall initiate negotiations with countries to establish international standards for government-supported infrastructure investment overseas. The negotiations shall cover issues including the sovereignty of countries receiving investment, anti-corruption, and environmental standards. The bill calls for various reports to Congress, including a State Department report about each mission's activities to promote U.S. economic and business interests, and a State Department and Department of Commerce report on commercial relations with foreign countries, including information on each country or region's political environment and investment climate.