Are the reasons for what Liberia is now grounded in the history of its begining?
Did it have any notable or official support back in the United States?
Were there attempts at organized nation building? such as the formation of a congress or constitution similar to the beginnings of the USA?
What reasons led to the lack of success in Liberia, especially considering the condition it is in now, and could it have been possible to build a Nation with what they had at the time? I imagine an African State built with laws and systems similar to those of an Early USA
I have done some research tangentially related to the American Colonization Society, so I posted a quick and dirty writeup in this thread about Liberia's relationship with the US a few months back. It should give you a decent start. Although I cannot answer a lot of your questions and am not really all that willing to condense the country's entire history in order to speak on the current state of affairs, I'm sure there are others who can speak more authoritatively on the subject. I'd also encourage you to head over to the original thread linked above and check out the other responses, which are excellent.
Here's the meat of my earlier, very bare bones summary:
Americans in the 19th century were grappling with how to deal with the effects of slavery and forged the idea that free blacks would find richer lives if returned to Africa. The American Colonization Society was founded in 1817 upon these ideals of emigration after emancipation. I won't get too in detail about this or a great deal of the nuance involved here because it seems like you are more interested in the evolution of legal status of Liberia.
Beginning in the 1820's, The American Colonization Society sent ships over to the Pepper Coast with volunteer freed blacks. They bought or forced locals off the land, established Monrovia, and began to grow colonies in the region.
By this point, we have a smattering of other societies from Maryland, Virginia, and other states who have formed their own colonies in the area. While there was some funding provided by the US Congress for these expeditions, the colonies remained in the hands of the directors of the societies.
In 1838, many of these societies merged to form the "Commonwealth of Liberia", which was still under the control of the directors of the American Colonial Society. Soon after, the board appoints the first black governor, a Virginian-born freeman named Joseph Jenkins Roberts. The economy is growing and reports from the Society express their pleasure in the developments thus far, "Who can doubt that the experiment of African colonization has been successful?" Twenty-Ninth Annual Report of the American Colonization Society (Washington: C. Alexander, 1846), p. 23.
However, there were continued difficulties with the British Government as traders failed to understand the international status of the Commonwealth as an independent sovereign entirety. These problems flared in 1846 when the message was sent to the British that "Liberia was not a colony of the US Government," and the British responded by not recognizing the sovereignty of the Commonwealth and instructing merchants to not abide by the Liberian trade duties (Twenty-Ninth Annual Report, p. 26).
Evidence suggests that this conflict with the British trading vessels was a primary cause in the American Colonial Society suggesting that Liberia declare itself independent, which they did in 1847 by forging their own Declaration of Independence and Constitution with JJ Roberts as the first president.
Liberia has been an independent State since. I could speculate as to why Liberia wasn't taken over during the Scramble for Africa, but someone more well versed in the African colonization would have to chime in.
For more information of the early formation of the American Colonization Society:
Early Lee Fox, The American Colonization Society, 1817-1840 (Baltimore: Johns Hopkins Press, 1919).