From what you've read...certainly that was the sales pitch for the 14th amendment. but its purpose was the elimination of State's rights, the 9th and 10th Amendments. The States have only an inferior authority over US citizens residing within their state. Example: if the Federal State has provided funding for schooling within any of the several States, then those schools are partly or wholly (depending on the amount of funding provided) Federal Schools. As such, the States cannot deny entrance to US citizens into these schools on such basis as, i.e., race, religion, sex, ect. These are "protections" of US citizens and the states cannot abridge these protections FOR US CITIZENS. The US citizen is given the "privilege" of living in a drug free society, by legislation per the 5th clause. Therefore the US citizen cannot manufacture, distribute or consume illicit drugs; and the State cannot make laws to abridge these laws, FOR US CITIZENS. These are merely extension of the "original intent" of the 14th Amendment, the intent that you have read about, so far, to protect the freed slaves by giving them "privileges and immunities" of a US citizen (citizens of the 14th Amendment created STATE). The 5th clause to the 14th Amendment creates the "living constitution" we sometimes hear about, as any new legislation is in fact, by extension, a part of the 14th Amendment.
There is no number, "enough", required to ratify the amendment. The Amendment itself is the formation of a new governmental system, it is a mini constitution within the Constitution. However many ratified it, they were ratifying it ONLY for themselves. There is not a number that when reached it becomes effective on the remainder, it is ONLY effective on each individual that chooses such. They were joining this newly formed society for and only for themself. Those who did not, those who have not and those who are not US citizens are still under the original form of government. Chances are, you do not know anyone who was born in one of the several States and IS NOT a US citizen. But the Expatriation Act of 1868 still valid today, establishes the right of anyone in these states to join, or leave, the new government. It was passed the day before the 14th Amendment was announced as ratified and effective.
The old system was never abolished, it still exist. But there are VERY FEW who are not member of the "new" system created by the 14th Amendment, very few who are born here and NOT Federal Citizens. The 14th Amendment establishes "privileges and immunities" for ITS citizens, the States, per the organic Constitution, establish "privileges and immunities" for THEIR citizens. But if you are born here or naturalized, AND UNDER THE JURISDICITON OF, then you are a United States citizen, and a United States citizen in which ever state you reside, whether that be Texas, New York, California, Mexico, China, Zimbabwe... any state foreign to the United States in which you reside you are still a United States citizen.
Reading Spooner, I would guess is was ignorance of the law that led people to accept US citizenship, and ignorance of the law that maintains the same today. But it was NOT ignorance on part of the lawmakers, thus the failure to ratify it LEGALLY, and all that that entailed. The legislatures of the several states new that it meant the end of State's rights and as such they refused to ratify it by freewill choice.
"Ehhh, What's ups Doc?" B.Bunny "Scwewy Wabbit!"E. Fudd
People's Awareness Coalition: Deprogramming Sequence