When you say Americans you are probably referring to residents of the United States, to which the answer would be no. There are no legal requirements pertaining to successfully completing a high school curriculum. Only those pertaining to truancy. Most states require children to attend school until the age of 16.
You need to graduate university not high school to get a degree
you need to graduate high school, and also need to graduate medical school
you need 1,000 to graduate
I believe it's 42 but, you may need to confirm that.
In high school, you can graduate with a high school diploma.
You need to be either in high school or college or you can be a graduate.
You graduate high school with a high school diploma.
You do not need to be a high school graduate to attend truck driving school. You do need to have a valid driver's license and in most states you need to be over 18 years old for insurance purposes.
You need at least 24 credits to graduate in Cincinnati, Ohio.
You need about 23 credits to graduate.
23.5
you have to have a minimum of 28 credits to graduate high school. But it varies in different school districts as well and different schools