
Wayne County, Ohio - In 1840, a David Bay was enumerated in Plain Township, Wayne County, Ohio, heading a household of seven, which included a male age 10 to 15 who could be Cyrus, age twelve at the time. Also enumerated was a female age 5 to 10, who could have been the ten year old Mary Bay who would later marry Benjamin Crull in Wayne County in 1847.
Nearly thirty years later, Mary and Benjamin Crull's son Marquis de Lafayette Crull married Cyrus and Lucinda Bay's daughter Lora Arecelia Bay in Henry County, Illinois. Was Mary Bay related to Cyrus Bay, perhaps a sister residing in 1840 in their father David Bay's household in Wayne County, Ohio?

Cook County, Illinois - From about 1880 through the mid-1890s, Cyrus and Lucinda made their home in and around Chicago, Cook County, Illinois, as evidenced by voter registration records. Lucinda died in Chicago in 1894. It is believed that Cyrus returned to Porter County, Indiana soon thereafter. Eldest son David Bay also resided in the Cook County area. Son Levi Bay, earning his living as a mail carrier, and his wife Margaret Hammond resided in Chicago. Daughter Ella Maude Bay and husband Charles Demmon both died in Cook County, Charles in 1912 and Ella surviving until 1941. Daughter Grace Bay married Charles Brown, this couple also making their home in Chicago.
Daughter Lucy Elizabeth Bay married Edward Dougherty Phillips in 1878 in Porter County at the home of her father, Cyrus Bay. Only one of their children survived into adulthood: Otis Edward Phillips, Sr., born in Chicago, Illinois, in 1891. Two daughters died tragically of typhoid fever, Irene Phillips in 1886 and Aurie Marie Phillips in 1903. Edward and Lucy made their home in Chicago until Edward's death in 1912. Otis Edward Phillips, Sr., married Helen Adele Cannady in Cook County, Illinois in 1914. By 1923, Otis Edward Phillips, Sr., his wife Helen, and his mother Lucy had relocated to Los Angeles, California.
Henry County, Illinois - Cyrus' oldest daughter, Lora Arecelia "Celie" Bay, married Marquis de Lafayette "Fett" Crull in Henry County, Illinois in 1878. The couple were enumerated in Henry County in 1880, but had relocated to Porter County, Indiana by 1900. Fett's mother was Mary Bay, who married Benjamin Crull in Wayne County, Ohio in 1847.
Lake County, Indiana - Levi Bay married Margaret Hammond in 1898. The couple established their home in Gary, Lake County, Indiana in 1903, raising a family of four children while farming and managing a milk cooperative. George Bay, the youngest son of Cyrus and Lucinda, also resided in Gary, Indiana, and died there in 1947.