Robert Dalton was born in 1868. His parents, Lewis and Adeline Dalton, had fifteen children including Emmett Dalton, William Dalton and Grattan Dalton. Adeline Dalton's brother was the father of Bob Younger, Cole Younger, and James Younger.
Bob's brother, Frank Dalton, became a deputy marshal. He worked with Heck Thomas but was killed while attempting to arrest a horse thief in November, 1887. Bob and his brothers Emmett and Grattan also served briefly as lawman. It was later claimed that the men were forced to leave the service after becoming involved in rustling.
In 1891 Emmett Dalton, Bob Dalton, Bill Dalton and Grattan Dalton robbed a train just outside of Los Angeles. George Radcliffe was killed during the raid and Grattan was captured. He received a 20 year sentence but later escaped. Over the next 18 months the Dalton gang robbed banks and trains throughout Oklahoma. Bob Dalton was considered the leader and other members included Bill Doolin, George Newcomb, Charlie Bryant, Bill Powers, Charlie Pierce, Dick Broadwell, William McElhanie.
After the gang stole $17,000 robbed a train at Pryor Creek on 14th July, 1892, a prize of $5,000 a head on the Daltons. Emmett later wrote: "Posting a 'Dead or Alive' reward for a man performs some dark alchemy in his spirit... He becomes fair game for every pot-shooting hunter... In quite a real sense he belongs thereafter to the living dead."
On 5th October, 1892, the gang decided to rob two banks in their home town of Coffeyville. Emmett and Bob went into the First National Bank while Grattan Dalton, Bill Powers and Dick Bradwell dealt with the Condon Bank. The men were spotted by a passerby, Aleck McKenna, who quickly alerted other members of the town.
The men of Coffeyville armed themselves with rifles and waited for the Dalton gang to leave the banks. In the shoot-out that followed, four members of the gang, Bob Dalton, Grattan Dalton, Bill Powers and Dick Broadwell were killed. Four local men, Lucius Baldwin, George Cubine, Charles Connelly and Charles Brown, also died.