Going back to the earliest data in the Social Security Administration database, 1880, (compilation from the year preceding) John, William and James are still the top three. If you know a little history, you might recognize King John, King William (William the Conqueror) and King James (as in the Bible edition) which might explain their popularity or maybe it was the other way around.
If you have English ancestors, their names are likely to resemble the normal distribution for the popularity of names with some possible notable exceptions for families with traditional or imaginative proclivities. Even if your ancestors came from someplace else, like Germany, Poland, Russia, or a Spanish speaking country like Spain or somewhere in South or Central America, the names given to your ancestors by their parents, likely conformed to the most common for that particular language.
Unfortunately, for future genealogists, naming patterns and even the most common surname patterns are undergoing a radical change. I went to pick up something up at the store for my married daughter and the store clerks could not find it in their files. Why? Because it was under her Tanner surname not her married name. She had given them her compound name. Where did my daughters get this practice? It couldn't be because their mother, my wife of 43 years, still uses her maiden name as her middle name when signing almost everything? Could it? In today's world, Mary Jones living with John Brown may be happily married.
What about really unusual or not so common names? Lucky is the genealogist who finds a relative with an unusual name. Do you realize how many people can have your same name unless your parents had the foresight to name you after some remote ancestor who had an unusual name? Do you also realize how much grief that unusual name has caused that person forced to tell his or her schoolmates that name when asked by a teacher? On the other hand, if your ancestors were not possessed with imagination and re-used the same names over and over, it can be extremely hard to differentiate the generations if all of the males were named John Smith or James Brown or whatever.
Here are a few things to look for in names when searching for relatives:
1. Watch for common naming patterns. In many societies there is a distinct pattern in naming children, first after a paternal grandfather, then the next child after the maternal grandfather, and so forth. In England in the 18th and 19th Century, the pattern was as follows:
- The first son was named after the father's father
- The second son was named after the mother's father
- The third son was named after the father
- The fourth son was named after the father's eldest brother
- The first daughter after the mother's mother
- The second daughter after the father's mother
- The third daughter after the mother
- The fourth daughter after the mother's eldest sister
You might want to check out the naming pattern in the particular country of your ancestors' origin.
2. Watch for use of ancestral surnames for proper names. My Grandfather's middle name was Parkinson, his mother's maiden name. (This is also another reason for not using ancestral names as some sort of security password, like the mother's maiden name etc.). Finding an unusual middle or first name may indicate the surname of some not-to-distant ancestor.
3. Look for people with the most unusual name first. When looking in a database for an ancestral family, if the father was named John Smith, perhaps one of the children was named Mordicai. You may not be able to identify someone from a sea of Johns, but Stetson or Remington might do the trick.
4. Don't get hung up on spelling. Prior to the mid-1800s very few people were "good" or consistent spellers. English and most other languages did not have any kind of standard spelling conventions until very recent history. If your ancestor was illiterate, it did no good asking him or her how their name was spelled. This rule goes doubly for surnames. Tanner has been spelled, Tamer, Tonner, Turner, and many other variations by indexers, enumerators, and all sorts of people filling out deeds, forms and about any other document imaginable.
5. Look for repetitious patterns in names, but not too seriously. This rule contradicts the first rule. Just because you find someone with the same name does not mean that person is the "right" person or even related. Just because there was a naming pattern does not mean your ancestors followed the pattern. They may not have gotten along well with the next ancestor in line.
6. Watch for people who changed their names. The reasons for name changes are practically infinite. Many immigrants changed their names to sound more native. The method of change is varied and inventive. For example German Klein could become English Small and so forth. One of my wife's ancestors came from Sweden and changed his name in Navy after the name of an island. Many people who suddenly disappear, may have just changed their names.
7. Watch for modified patronymics. Patronymics are equivalents of "the son of..." or "the daughter of..." Many genealogists recognize -son, -sen as patronymics, but how about Mac or Ap or more unusual ones like Fitzroy which means, in essence, "king's son" usually illegitimate. In Spanish most all of the surnames ending in -ez (i.e. Lopez, Hernandez etc.) are patronymics. At some point, most patronymic systems, such as the Danish one, broke down with a time period of a mixture of standardized surnames and continued patronymics, even with the same person or family. Jens Petersen, may have children named Petersen as well as Jensen.
That's enough examples for now. It helps to read a little and study some also. Knowledge is power, especially in genealogy. Ignorance is not bliss. It is just ignorance.