Now Playing: Hidden America: Children of the Plains

Now Playing: Hidden America: Stand Against the Wind

Now Playing: Hidden America: Changing Dreams

Now Playing: Hidden America: Tiny Dancer

Now Playing: Former Obama speechwriter now writes comedy in Trump era

Now Playing: Sean Spicer on his tumultuous time serving President Trump

Now Playing: How hackers tap into tech's vulnerabilities from cars to voting machines

Now Playing: Robin Roberts' emotional health journey to milestone 'birthday'

Now Playing: Devastating earthquake in Mexico leads to race for survival

Now Playing: How rising star Charlie Puth composed 'See You Again' in minutes

Now Playing: The war of words between US and North Korea

Now Playing: 'Despacito' co-writer Erika Ender sings unplugged version of hit song

Now Playing: Former Boy Scout alleges years of abuse from troop leader

Now Playing: The making of 'Despacito' and its rise to be summer's top song

Now Playing: Puerto Rico braces for Hurricane Maria impact

Now Playing: 'Posse' program helps students stay in college

Now Playing: Heroes of Houston jump into action to save neighbors

Now Playing: After Hurricane Harvey, the long road to recovery begins

Now Playing: Hurricane Harvey evacuees airlifted out of horrific flood zones

Now Playing: DACA recipients ponder their future as Trump continues to review the program