Considering generations in genealogy

When working with genealogy, it is important to remember the number of generations which are likely to occur in a given span of years. We generally figure three or four generations to every 100 years — in rare instances only two, in others five.

The average span from one generation to the next is about 25 to 30 years. In the space of 350 years, you can estimate that there will be roughly 12 generations. At the tercentenary of the landing of the Pilgrims at Plymouth, most of the applications for membership in the Society of Mayflower Descendants were of the 10th generation in descent, few were of the 9th and few were of the 12th.

Naturally there are exceptions. For example, think about the English Lord Maurice Berkeley who was born in 1281. In 1289, he was married at the age of 8 to an heiress of considerable property who also was 8-years-old. Their first child, Thomas, was born about 1291. Their son who was another Maurice also married at the age of eight to another heiress.

Then there was King Henry I born in 1100 in England. Henry and his wife Matilda had three children, a son who died in infancy, a daughter, and another son, William Andelin. In addition to his two surviving children, King Henry had at least two dozen illegitimate children. Try to separate that on a pedigree chart.

In today's world, it is not uncommon to find pictures of a five generation family. Think about a great,-great-grandmother holding a baby on her lap. She would normally be in her 80s, or even her 90s. Five generations in less than a century is now fairly common.

Even so, the span between each generation is still 20 to 30 years. Pretend that our great-great-grandmother was born in 1880; her son, a great-grandfather was born in 1905, his daughter, the grandmother in 1927, her daughter, the mother in 1948, and the child in 1970.

Still with me? At the other extreme, it is not unusual for a man to be 40, 50, or 60 before he marries or his first child is born. An octogenarian may father children.

Sometimes you might find a really large family with more children than seems probable. This gets a bit confusing when dealing with second marriages. Check the birth dates of all the children listed for one family. Make sure all the ages mentioned are supported by additional documentation.

Consider a couple's marriage date — two different marriages mean two different dates, sometimes a short period apart. Check every source for inconsistencies. It's not unusual to find that a person died before he/she was born.

Watch for typographical errors citing the wrong century or transposing numbers such as 1942 rather than the correct date of 1842 or 1756 rather than 1765.

For each ancestral family, today's genealogical standards require careful documentation for every name, every date, every place, every relationship and especially every printed and oral source. Stay focused and good hunting.

Carole Etchells Cross is a member of the Coshocton County Genealogy Society, which meets from 7:30 to 9 p.m. the third Tuesday of every month at the Coshocton Public Library. For more information, visit coshoctongenealogy.wordpress.com.