Bigelow's was the second speech in two years on the topic. John B. Chapman gave a speech on the same day in 1851. But, because Chapman himself didn't play nice with the Democratic machine in greater Oregon, his secession effort ended dead in its tracks. Chapman left the territory by the time a Bigelow inspired convention happened in November 1852 at Monticello (where Longview is now).
The Northern Oregonians along Puget Sound argued that the Oregon Territory eas too big. So, it makes sense to split it. And, if you're going to split it, you should split it into a northern and southern territory that would both have seaports. Also, evenly divided territories would be competitive, and through competition, would improve each other.
Also, and we hesitate to bring this up, but Northern Oregonians haven't gotten much from the Willamette centered government. Makes sense, you know, vote in your own interest and all that. But, if we could be separate, would could take care of our own.
Iit was a possibility that certain parts of what are now Washington State were seriously considering not joining the territorial secessionists. From the Columbia (Olympia) newspaper in November 1851:
Living, as they do, on the boundary line between the two divisions of Oregon -- in constant intercourse with the southern portion, with whose citizens they transact a large proportion of their every day mercantile and commercial business, it is but natural to suppose that their sympathies are pretty equally divided between north and south.Today the folks along the southwest border in Longview and Vancouver still seem to face further towards the south than north to Seattle.
Even the location of the convention in 1852 was chosen to be in the heart of these just north of the river communities so as to convince their representatives to attend. If the location had been chosen in Olympia (writes the Columbian editor), the lack of enthusiasm from Columbia River residents would've prevented them from attending at all.
So, what would have happened to our territorial independence if the meeting was held in Olympia and not in Monticello? Would we have ended up with a new Puget Sound centric territory (and then state)?
While the population of Puget Sound was certainly growing, the balance of people still lived along the Columbia. It is possible that the Puget Sounders needed Columbia River folks to reach the necessary population for a new territory.
Also, it is possible I imagine that a Puget Sound territory would not have included any east of the mountains territory if not for the lower Columbia.
In the end, I think the deciding factor of our state's separation from Oregon was the Columbia newspaper, founded as Olympia's first newpaper just months before the November convention. It is no coincidence that Bigelow's Independence Day Speech was published in the paper's first edition. In that edition, the paper was also advertised as being neutral in politics, for Oregon in general, but specifically for the interests of Northern Oregon.
It also never advertized itself as being from "Olympia, Oregon Territory." Rather (as Dennis Weber points out), in its early editions, the location of the Columbia newspaper was labeled as being, "Olympia, Puget Sound."