What it does
A plain-language summary is coming. Here is the official summary from the Congressional Research Service:
All-American Flag Act This bill prohibits agencies from using funds to procure a U.S. flag unless such flag has been manufactured in the United States from materials that have been U.S. grown, produced, or manufactured. The bill specifies exceptions to this prohibition, including an exception if flags of satisfactory quality and sufficient quantity cannot be procured as needed at market prices.
How Congress voted
This law passed by voice vote or unanimous consent, so there is no record of how individual members voted.