Charles is an English name... German would be Carl.Perhaps this is your Charles ship manifest info?
Name: Carl Rehfeldt Arrival Date: 18 Nov 1856 Birth Date: abt 1841 Age: 15 Gender: Male Nationality: German Place of Origin: Mecklenburg Port of Departure: Hamburg, Germany Destination: United States of America Port of Arrival: New York Port Arrival State: New York Port Arrival Country: United States Ship Name: N Coopelk He was arriving with Johann REHFELDT age 51, Johanna age 50, Johanna age 18 and Maria age 14
Perhaps he became a Citizen by way of his having served in the US Civil War
"Naturalization and the Civil War An Act of 17 July 1862, stated: "any alien, of the age of twenty-one years and upwards, who has enlisted, or may enlist in the armies of the United States, either the regulars or volunteer forces, and has been, or may be hereafter, honorably discharged, shall be admitted to become a citizen of the United States, upon his petition, without any previous declaration of intention to become such; and he shall not be required to prove more than one year's residence." (Act of July 17, 1862, 12 Stat. 597, section 21)"
I find Civil War records for John RAYFIELD aka John Brown as well as his pension papers filed 1879
Robert Jerin Croatian Heritage Museum Cleveland Ohio