It appears we may have a match! Here is what I know so far about them.
JOHN JAMES BOWMAN was born December 06, 1875 in Roane Co.,TN, and died August 27, 1951 in Tiburon, Marin, California.He married LETTY ELIZABETH HARPER, daughter of ROBERT HARPER and LUCINDA ARRINGTON.She was born October 10, 1885 in Marshall, Madison, North Carolina, and died January 26, 1970 in Mill Valley, Marin, California. Children of JOHN BOWMAN and LETTY HARPER are: MAMIE L BOWMAN, b. 1906. PAUL L BOWMAN, b. 1909. BESSIE BOWMAN, b. October 01, 1910, Knox Co, Tennessee; d. December 1910, Knox Co, Tennessee. KENNETH G BOWMAN, b. 1912. RUTH A BOWMAN, b. 1914. ROY H BOWMAN, b. February 15, 1915. EDWARD W BOWMAN, b. 1922, Idaho.
John James moved his family to Idaho sometime after the 1910 census. Moving with them was his brother Jackson and his family. Not sure exactly when they moved on to California. These two were the only ones in the family to move out of TN. They had 10 brothers and sisters. Let me know if this fits with what you find. My e-mail is firstname.lastname@example.org Looking forward to hearing more from you!