Felix Grundy Walker was born in Madison, Illinois on October 11, 1835 to Richard Jefferson and Nancy (Cavender) Walker. He grew up in Illinois with 6 siblings: Mary Elizabeth "Liz" (1822-1883); Richardson (1831-1914); Samuel (1835-1891); William Lockwood (1839-1891); Nancy (1841), and Emma (1857).

On October 12, 1856, Felix married Eliza Ann Campbell in Adams County, Illinois. They had 3 children, Sarah Adeline (1858) was born in Illinois. Around 1859, they relocated to Jack County, Texas, where his parents and several siblings had located. George W. (1860), and Mary Jane (1862) were both born in Jack County, Texas. Felix's wife, Elizabeth, was killed by Indians in 1863 while she went to fetch water. She was holding her baby, Mary Jane, in her arms at the time. Felix took the children and moved back to Illinois.

On the 31st of December, 1865, in Concord, Adams County, Illinois, Felix married Martha Jane Foster, who was born in 1844 in Kentucky. They had 10 children together. Their first child, Anna May, was born in 1867 in Illinois. Franklin was born in Illinois in 1868.

In 1869, Felix and Martha moved their growing family to Chariton County, Missouri. They settled on a plot of land and lived in tents while he farmed and until a barn and house could be built. They lived on that property for twelve years. Five more children were born to them on that farm, including Lucy, Nora, Edward, Kate and Guy. In 1880, Felix sold his farm to Michael Sauer (who would one day be the father-in-law of two of his sons) and moved to another farm within Chariton County. On this farm the last three children, Felix "Grundy", Cora and Mattie were born and it would be where Felix would spend the rest of his life.

According to his obituary, "around 1890 Felix was converted and united with Bethel Christian Church where he remained a member the rest of his life". Felix was unwell during his latter years and died at his farm, located about 8 miles northeast of Brunswick, MO, on August 30, 1920 at about 2 o'clock on a Monday morning at the age of 85.