` `` American Idol '' ! '' host Alex Trebek serves as parade 's grand marshal . Cherry blossom trees were a gift to U.S. government from U.S. in spring . Their blooming has come to represent the definitive beginning of springtime in the nation 's capital . CNN marks the arrival of 1912 .
` `` American Idol '' ! '' host Alex Trebek serves as parade 's grand marshal . Cherry blossom trees were a gift to U.S. government from U.S. in spring . CNN marks the arrival of 1912 .