Before the caucus started, Clinton planned a "victory party" at Drake University in Des Moines.
We checked out the best outfits from party-goers on Monday night.
Some went for classic campaign looks using Hillary's 2016 logo.
Alexandra Svokos
"Hillary 2016" t-shirts abounded -- along with sweaters to account for the Iowa cold.
Alexandra Svokos
These party-goers got creative, taking Hillary's "fighting for us" slogan literally.
Alexandra Svokos
Your squad can't go wrong with big pins explaining your candidate's platform.
Alexandra Svokos
"Precinct Leader" pins indicated the real MVPs of the night -- the people who led caucuses to get the vote for Hillary.
Alexandra Svokos
A Hillary pin can be fashionable and functional.
Alexandra Svokos
Wondering how to make your cute hat even cuter? Add a sticker!
Alexandra Svokos
When you're in a bind, accessorize with tape.
Alexandra Svokos
Tape can also be used to make giant versions of Hillary's 2016 logo.
Alexandra Svokos
The Human Rights Campaign, the LGBT rights group that endorsed Clinton last month, was well represented.
Alexandra Svokos
SLAY.
Alexandra Svokos
NARAL Pro-Choice America, a pro-abortion group that endorsed Clinton, showed support with t-shirts.
Alexandra Svokos
And Planned Parenthood, which -- you guessed it -- also endorsed Hillary, was there in shining colors.
Alexandra Svokos
Never underestimate the power of a sensible Planned Parenthood pin.
Alexandra Svokos
Some party-goers classed it up...
Alexandra Svokos
...while others went all out.
Alexandra Svokos
No matter how people chose to accessorize, excitement was in the air as Hillary got past her first challenge on the road to becoming the Democrat's presidential nominee.