A child’s USC parent must reside or be physically present in the US to “transmit” citizenship to the child. The USC’s residence should be the principal dwelling place of that person without attention to intent, such as the case of Savorgnan v. US, 338 US 491 (1950). In Sessions v. Morales-Santana, the United States Supreme Court ruled that the different physical presence for unwed mothers and fathers violated equal protection.
Physical presence need not be counted by the minute, as per 137 S.Ct 1678 (2017). If the parent is a naturalized US citizen, the time before and after naturalization may be counted, as indicated in Matter of M-, 7 I&N Dec. 643 (RC 1958). A parent should not be prevented from residing in the US due to war or illness but may do so when he/she was barred by the government due to a misinterpretation of the law, as stated in Matter of Navarrete, 12 I&N Dec. 138 (BIA 1967).