The goal of this organization is to help vampires and other creatures of the night to adjust to living amongst civilized races. They serve as a congregation of creatures to offer support, aid and information to those coming in to their domains.

They are a charity organization mainly, helping vampires and such to settle down and fit in to the community, but they also tend to serve as ambassadors for their kindred to the communities in which they reside. Smoothing over discrepancies and serving as a sort of police force to keep everything in order.

This organization is widespread but loosely connected. Vampires who congregate under the goals of the Undernation might elect individuals to serve particular roles.
They operate similar to a club or government, but also akin to a religious organization.

When a congregation of the Undernation first comes together they might hold an election amongst themselves to select a "president", otherwise known as a "king" to garner respect from other covens unaffiliated with the Undernation.
The president stands in judgement and has the final say on any congregational activities, and the actions and decisions of the president are held up to Constitution of the Undernation.
Elections are held annually for this position unless the president is found guilty of violating the Constitution.

"Elders" are chosen as officers and guides to the congregation. Creatures who've lived more than a century, who believe in the goals of the Undernation and its Constitution. They are shepherds of the congregation and also serve various roles such as "treasurer", "sargent at arms", or as representatives for the congregation to the president.
Each Elder holds their office until they step down or are found guilty of violating the Constitution.

For the protection and regulation of their members, a police force is built and organized by a sheriff.

The Vampire Undernation was founded a very, very long time ago by and for vampires. Many of the oldest vampires cannot tell when it began, and the majority of its founding members have not survived to this age.
Many with long memories or those who study history would claim that the Undernation has always existed in one form or another, surviving in the shadows of nations past and present and likely will still exist far into the future.

It was first founded as a solidarity of vampires who came together to pool their resources and combine their efforts to ensure the survival of their species. From there it grew and spread out across the continent.
Over the millennia its membership has risen and fallen, as a whole they grew and learned how best to coexist with the creatures they relied on for sustenance, and from this the Constitution of the Vampire Undernation was born.

Since then the Undernation has grown to include not just vampires, but other creatures who rely on mortal kind to exist and are hated as a result.

Rivers of Life, Veins of Blood
Blood and Lust