That and an extensive family history are documented in the three family trees, dating back to the 1700s, that Long has compiled over the years -- that of Isaac Long, Dr. Peter Fahrney and Johannes Slifer.
Omer Long said he started collecting information on the Fahrney family in the 1940s, but didn't print it until 1993. While researching the Fahrneys, he came across bits and pieces about the Longs and Slifers, and eventually had that information printed and bound in book form.
A Long family picnic in Illinois was a gold mine of information, with Long, Slifer and Fahrney family members in attendance.
"I got all kinds of names. It seemed as though everyone here went to Ogle County, Illinois," Long said.
Slifer came to the United States from Switzerland, under the name of Johannes Scheiffer, and settled in Bucks County, Pa. Omer Long's grandfather was Otho Slifer.
Long's grandmother was Peter Fahrney's daughter.
"There's a lot of human interest in those books," said Gwen Long, Omer's wife of 61 years.
Even after years of research, it's still unclear whether Isaac Long died from a fall off a fence or whether a bull got him.
Omer Long admits not all the family is happy with some of the information that's been included, most notably the alcoholism of one of his grandfathers.
Then there's the family member who hanged himself in jail in 1878.
Long's own history is interesting. Born and raised in Washington County, he graduated from Williamsport High School in 1939, attended Bridgewater College for two years and graduated from George Washington University with a degree in engineering in 1943.
Long married Gwen Honsaker on Christmas Eve 1946. They have a daughter and son, five grandchildren and three great-grandchildren.
Long retired in 1983 from the U.S. Postal Service with 20 years of service. He was the general manager of the Engineering Office in Washington, D.C., and received a patent for a package-sorting machine.
A longtime member of Downsville Church of the Brethren, Long, with Gwen's help, devoted 20 years to maintaining Manor Church Cemetery in the Fairplay, mowing and trimming the 8-acre property until he started having health problems a few years ago.
Long's parents had the 100-year farm, part of the original 500 acres Isaac Long purchased and divided into three parts. Omer Long said it's still in the family, owned by his nephew Galen Long.
Omer Long said that now that people know of his genealogy work, they send information directly to him.
You won't find any Internet research in Long's family trees. He doesn't trust the accuracy. For instance, he said, an Internet search would have turned up Jacob Long's book as a resource.
He's also found information that won't be included because he's unwilling to taint his research with information that he can't verify.
"I found a will in the Washington County Courthouse from 1789. I didn't accept it because I couldn't identify it as the exact will because there was no wife's name listed," Long said.
Generations to come can expect to find Omer Long's family trees intact and updated, thanks to other family members who have expressed an interest in continuing his work.