It is from this structure of steps and requirements that U.S. naturalization evolved. While we still require new citizens to be persons of "good moral character," limitations based on gender or race eventually disappeared, while new requirements were introduced by subsequent legislation. In the ongoing effort to implement a uniform rule, Congress repeatedly amended and expanded on the rules of naturalized citizenship.
The naturalization provisions of the Act of 1795 replaced those of the 1790 Act and made changes to the residency requirements while adding several important steps to the naturalization process. The period of required residence increased from two to five years in the United States and from one to two years in the state of residence. One change introduced by the 1795 Act was the Declaration of Intention requirement, or "first papers." This created a two-step naturalization process.
Immigrants intending to naturalize had to go to their local court and declare their intention at least three years prior to their formal application. In the declaration, the immigrant would also indicate his understanding that upon naturalization, he would take an oath not only of allegiance to the United States but also of renunciation of his former sovereign. In addition to the declaration of intention and oath of renunciation (scroll to last paragraph of document), the 1795 Act required all naturalized persons to be "attached to the principles of the Constitution of the United States" and be "well disposed to the good order and happiness of the same."
Three years later, one of the "Alien and Sedition Acts" temporarily raised the residency requirement. The Naturalization Act of 1798 increased the required term of residence to fourteen years in the United States and prohibited the naturalization of alien subjects of nations with which the United States was at war (enemy aliens). It also required all aliens resident in and arriving in the United States to register with their local courts. Like the other alien and sedition acts, the 1798 naturalization law was implicitly repealed in 1802.
A new Act of April 14, 1802 restored the residency rules from 1795 (five years in U.S., one in the state of residence) and largely reestablished the system as it existed prior to 1798. The 1802 Act also answered a question long associated with residency requirements: What evidence should the court demand that the applicant had resided in the U.S. or the state the required period of time? The new legislation declared the applicant's sworn testimony was not adequate. He would have to provide two witnesses who would testify, under oath, to his residence in the United States. The general elements of the 1802 naturalization law remained the law of the land for more than a century. Congress made relatively few adjustments to the law during that time. Nevertheless, some of those changes promoted uniformity while others lessened the requirements for naturalization in certain cases, and still others denied naturalized U.S. citizenship to entire classes of persons. (text from INS history)