The chronology and character ages tells the years the series took place and events that happened. This is based on producer David Dortort's conception of the series in 1959.
Season One: 1859-1860
Season Two: 1860-1861
Season Three: 1861-1862
Season Four: 1862-1863
Season Five: 1863-1864
Season Six: 1864-1865
Season Seven: 1865-1866
Season Eight: 1866-1867
Season Nine: 1867-1868
Season Ten: 1868-1869
Season Eleven: 1869-1870
Season Twelve: 1870-1871
Season Thirteen: 1871-1872
Season Fourteen: 1872-1873
Birthyear and Birthplace
Benjamin Cartwright: 1809
Birthplace: Boston, Massachusetts
Adam Cartwright: 1830
Birthplace: Boston, Massachusetts
Eric "Hoss" Cartwright: 1836
Joseph Francis Cartwright: 1842
Birthplace: Ponderosa Ranch, Nevada
Character Ages in "A Rose for Lotta"
September 12, 1859
Ben Cartwright: 50-years-old
Adam Cartwright: 29-years-old
Hoss Cartwright: 23-years-old
Joe Cartwright: 17-years-old
1809: Ben Cartwright is born.
1828: Ben marries Elizabeth Stoddard.
(Ben: age 19).
1829: Elizabeth gives birth to Adam.
(Ben: age 20).
1832: Ben marries Inger Borgstrom.
(Ben: age 23, Adam: age 3).
1836: Inger gives birth to Hoss.
(Ben: age 27, Adam: age 7).
1841: Ben marries Marie DeMarigny.
(Ben: age 32, Adam: age 11, Hoss: age 5).
1842: Marie gives birth to Joesph.
(Ben: age 33, Adam: age 12, Hoss: age 6).
1848: Adam goes to college in Boston, Massachusetts.
(Ben: age 39, Adam: age 18, Hoss: age 12, Joe: age 6).
1859: The arrival of Lotta Crabtree. The discovery of gold by Henry Comstock and birth of Virginia City (flashback episode).
(Ben: age 50, Adam: age 29, Hoss: age 23, Joe: age 17).
1860: Sheriff Roy Coffee arrives in Virginia City to work there, protecting its citizens and enforcing law and order.
(Ben: age 51, Adam; age 30, Hoss: age 24, Joe: age 18).
1861: Civil War begins in America.
(Ben: age 52, Adam: age 31, Hoss: age 25, Joe: age 19).
1862: Clay Stafford arrives in Virginia City and it's discovered he is Joe's half-brother. Evidently, he chose to use an alias name for personal reasons, since Marie was married to Jean DeMarigny, when he was conceived in New Orleans. They were married for one month and separated because Jean found Marie with another man in their bedroom. Jean's mother hated Marie, so she hired the other man to make her look bad, and Jean left her. At the time, she was already pregnant, and when the baby was born, it was taken from Marie by Jean's mother, who later told her it died from a disease.
Jean later came to Nevada to work as foreman of the Ponderosa and he was killed in a cattle stampede after saving Ben's life, who took the news of his death to New Orleans, where he met Marie in 1841. He uncovered the ugly lies about Marie, forcing Edward Darcy to confess he was the man who disgraced Marie in the bedroom. She and Ben married a short time later. Clay's age and year of birth are unknown, but he is at least a few years older than Joe's age.
(Ben: age 53, Adam: age 32, Hoss: age 26, Joe: age 20).
1863: Clem Foster arrives in Virginia City and is hired as the Deputy-Sheriff.
(Ben: age 54, Adam: age 33, Hoss: age 27, Joe: age 21).
1865: Adam leaves the Ponderosa.
(Ben: age 56, Adam: age 35, Hoss: age 29, Joe: age 23).
1868: Candy Canaday arrives in Nevada.
(Ben: age 59, Hoss: age 32, Joe: age 26).
1870: Candy leaves the Ponderosa and the arrival of Jamie Hunter.
(Ben: age 61, Hoss: age 34, Joe: age 28).
1872: The death of Hoss, Joe marries Alice Harper, Candy returns to the ranch, Joe's wife is savagely murdered and the arrival of Griff King on the ranch.
(Ben: age 64, Hoss: age 37, Joe: age 30).
1873: Ben, Joe, Candy and Jamie continue onward in their life on the Ponderosa.
(Ben: age 65, Joe: age 31).