The 1870 census of Sutter County California has a Lemuel Pitt, 13 Illinois, with Robert 41 England and Harriet 35 New York.  Sister L.A. 11, Fred 3, and grandmother Ann Pitt are also there.

1885 Clarke County Iowa has a Lemuel Pitt, born in Illinois, 28 years old.

PITT, section 11, Knox Township, is a  native of London, England, where he  was born October 5, 182S, a son of William and Ann (Dean) Pitt. When he was about four years of age, his mother, then a widow, emigrated with her family to America, landing in New York City, where they made their home for a number of years. At the age of fourteen years our subject began learning the carpenter's trade, at which he served an apprenticeship of four years. After serving his apprenticeship he went to Adams County, Illinois, where he lived for fourteen years,
engaged in agricultural pursuits. At the age of twenty-five years he was married to Miss Harriet Dunton, and to this union were born six children, of whom three are deceased. The names of those who still
survive are — Lemuel M., Lillian and Frederick Eugene. In i860 Mr. Pitt went with his family to California, where he made his home for eighteen years, being extensively engaged in wheat raising. In 187S he located in Clarke County, Iowa, and has since resided on his present farm in Knox Township, where he has i20 acres of choice
land under his cultivation, a large and substantial residence surrounded by shade and ornamental trees, a good orchard, and commodious out-buildings for his stock. The mother of our subject was a daughter of Thomas and Mary (Waite) Dean, natives of Somersetshire, England, her mother being a member of the prominent Waile
family of London. ,. '

Lemuel M. Pitt claimed a quarter in December 1904 from the El Reno, Oklahoma Territory in 13N 20W of the Indian Meridian. (Custer County).

Decatur County Journal-Iowa Thursday, February l5, l9l7 ROBERT PITT was born in the city of London, October 5th, l828, and died at the home of his son, FREDERICK E. PITT, near Van Wert, Iowa, January 22nd, l9l7. He was 88 years, 3 months and l7 days of age. When ROBERT was five years old his widowed mother emigrated to New York City with her three sons, all of whom are now deceased. In l846 ROBERT emigrated to Quincy, Illinois, where he was united in marriage with MISS HARRIET DUNTON. To them were born six children, ALICE who is deceased, L.M. PITT, of Oklahoma; PAUL PITT, deceased; MRS. LILLIAN GODFREY, of Los Angeles, California; GEORGE W. PITT, deceased, and FREDERICK E. PITT, of Weldon, Iowa. During the rush for California gold in l8??, the deceased crossed the plains with three ox teams. While there his wife died and he later married MRS. SARAH A. PULVER, who came with him to Clarke County, Iowa, in l877. She preceded him to the great beyond in August, l9ll and her body was laid to rest in Maple Hill Cemetery at Osceola. After this date the deceased made his home with his sons who in turn resided on his farm north of Van Wert. Following the services at the home, members of St. John's Lodge of Osceola, of which he was a member, performed the funeral rites at the grove in Maple Hill Cemetery at Osceola where the body was laid to rest at ll a.m. Tuesday, January 23. ROBERT PITT was a good husband, a kind father and a highly respected citizen. The kind deeds of his life will continue to live in the hearts and memories of a host of relatives and friends.

 

Lemuel  did a cash-claim in 1891 in section 7, 4N 46W

Simply because there's no other census or newspaper listing, this is my only match.

Robert Pitt in 1900 Decatur County Iowa  is 71, and has been married 27 years to Sarah A. 70.  Frederick E. 33 and Robert are both farming.

All three are still in Decatur County in 1910.

In 1920 and 1930 Frederick is still there, but single.

1900 Washita, Custer County, Oklahoma Lemuel M. Pitt, born June 1856 in Illinois, father born England, mother New York, is single, farming.

1910 Custer County has a Lemuel ( Samuel, still single at 53.  He's a bookkeeper for a telephone company.

FindAGrave has a Lemuel Moses Pitt in  Red Hill Cemetery, Hammon, Oklahoma. June 23, 1856 - May 17, 1935

Custer County Probates show a F E Pitt filed 24 Mar 1936, a L M Pitt filed 21 May 1935