Selina Wang reports on the historic day in the race for the White House as Vice Pres. Harris secured the Democratic party presidential nomination, becoming the first Black woman and first Asian American nominee for president for a major party; Mireya Villarreal has more on the emotional homecoming of the three freed Americans who are back on U.S. soil after the prisoner exchange with Russia; Rebecca Jarvis has details on the stock market plunge that was fueled by lower than expected jobs numbers; Whit Johnson reports on some of the history-making moments from Team USA at the Olympics in Paris; and more on tonight's broadcast of World News Tonight with David Muir.