From Milam and Greene's website:

When talking to our customers and fans across the country, there was an overwhelming ask to release a Milam & Greene Bottled in Bond. The people asked, so we made it happen!
Bottled in Bond is a designation that was created in 1897 by way of the Bottled in Bond Act. It was done to protect the integrity, quality and authenticity of aged whiskey in America, because people were adding all sorts of stuff to spirits at the time. The Bottled in Bond Act of 1897 dictates that anyone using the title Bottled in Bond must meet the following criteria:

• The spirit must be produced in a single distilling season by a single distillery
• The spirits must mature in a U.S. bonded warehouse for a minimum of four years
• The aged spirits must be bottled at exactly 50% ABV / 100 Proof