The Goblin Declaration of Freedom

Content Warning: Slavery, Violence

Goblinoids have long been enslaved, primarily by the Orcish, though they have been mistreated by other peoples as well. From the very beginning, it was common to separate goblins from their families through sale, fearing that a cohesive unit with enough members might cause an uprising.
From the goblins' perspective, there wasn't any point in rebellion as long as they knew they could not win. However, they did grow in numbers, and eventually, learnt how they could abuse the value that their masters saw in them.
The start of the widespread Goblin Liberation Front was one secret, illegal meeting, one act of rebellion that would take over the hearts of all goblinoids like wildfire.
Most of all, it started with one message on the wall, written in orc blood.

We were never yours

— Anonymous goblins

As no one had seen the goblinoids painting the message, or even noticed any of their slaves doing anything out of the ordinary, hunting the culprits became difficult.
No one had seen anything. Though the blood was clearly orcish, no bodies of orcs had been found, though there were a few missing persons.
For the orcs, it became difficult to arrange for a suitable punishment. After all, no one knew what had happened and it would be a waste of valuable resources to punish all of the goblins in the area for, presumably, the deeds of a few.
Both among goblins and orcs, the news of what had happened had spread like wildfire. This one act, determined by a select few, set off a chain reaction, leading to the creation many Orcish missing persons reports.
Groups of goblins would unite to be able to target single orcs without ever being noticed. Naturally, they left many messages to their oppressors, though none as well known as the first.
'We were never yours' has become somewhat of a mantra, a belief shared between the entirety of the goblinoid communities. It is something to still raise your glasses towards, and not only on independence day