In a previous post I asked why Thomas Casbon left Ohio for Indiana. It seems that he was making a good go of things in Ohio. He owned his own farm. He raised his children to adulthood there. We’ll probably never know exactly why he decided to move, but it’s likely there was more than one reason.
Thomas Casbon migrated from Holmes County, Ohio, to Porter County, Indiana. Source: Johnston, K. “United States of North America, eastern states.” Engraved & printed by W. & A.K. Johnston, Edinburgh. William Blackwood & Sons, Edinburgh & London,(1861) David Rumsey Historical Map Collection http://www.davidrumsey.com/ (Click on image to enlarge)
First, two of Thomas’ sons, Sylvester and Charles, had already moved to Porter County in 1859 and 1862, respectively. Here is a description of Sylvester’s move, from The History of Porter County:
Then acting under the persuasion of a friend Mr. Ellsworth, who had settled in Porter county, Indiana, and also from his own wish to locate further west, Mr. Casbon came to this county in 1859 and began teaching in what was then known as the Ellsworth school, which he conducted successfully for three terms. He also taught one term in Boone Grove and one term in the House school, as it was called then, but later known as Boone Grove school. 
“Ellsworth” in the preceding paragraph is a probably a misspelling of Aylesworth. The Aylesworth family history is intimately tied with that of the Casbons. When Thomas and family arrived in Wayne County, Ohio, two brothers, Ira and Philip Aylesworth, were already living there with their extended families.  In addition, another one of their brothers, Giles Aylesworth, had moved from Wayne County, Ohio, to Porter County, Indiana in 1842.  Another Ira Aylesworth, Philip Aylesworth’s son, moved to Porter County in 1845.  It’s unclear which “Mr. Ellsworth” (Aylesworth) influenced Sylvester to come to Porter County. I think it was probably either Elias or Sylvenus Aylesworth, grandsons of Philip Aylesworth.  They were both born in Ohio and were contemporaries of Sylvester Casbon. At some point they moved to Boone Township in Porter County, and were both living there in 1860. 
I should also point out that Sylvester married Mary Adeline Aylesworth, daughter of Giles, in Porter County.
Charles Casbon’s biography in The History of Porter County suggests that he was influenced to move westward by the New York Herald (mislabeled as Tribune in the biography), whose famous editor, Horace Greeley, frequently exhorted his readers to “Go west, young man, and grow up with the country.”
It was partly with the inspiration derived from the Tribune, and also from the spirit of pioneering which had possessed his father before him, that caused Charles Casbon on arriving at his majority to start for the west. In company with a friend, George Bittner, in March, 1862, he arrived at Valparaiso, a small place at that time, where he paused in his journey and in this vicinity has remained ever since, to his own profit and to the benefit of the community. 
There is one problem with this version of events: Horace Greeley did not use the phrase “Go West, young man…” until 1865,  well after Charles left for Indiana! However, the statement that he went with his friend, George Bittner, sounds reasonable. An entry for George Bitner, born about 1844, is listed in the 1860 census for Washington Township, Holmes County, Ohio,  just five entries away from the listing for Thomas Casbon. This means they would have been neighbors. Assuming this is the George Bittner who accompanied Charles Casbon, he must not have stayed in Indiana, since he is listed in Holmes County, Ohio in later censuses,  and died in adjacent Wayne County in 1927. 
Not only did Sylvester and Charles move from Ohio to Indiana, but their older sister Mary Anne married Elijah Priest in 1853,  and moved to Porter County sometime after 1860, when the census recorded them living in Holmes County, Ohio. 
The fact that three of his children were in Indiana was probably a major reason that Thomas decided to make the move himself.
In addition to his children, many others were migrating from Ohio to Indiana. Some of the earliest settlers of Porter County came there from Wayne County, Ohio in the early 1830s.  A fairly steady stream of residents migrated from Wayne and Holmes Counties through the 1860s. ,
A partial list of individuals who migrated from Wayne & Holmes counties, Ohio, to Porter County, Indiana (Click on image to enlarge)
There were probably many factors behind this migration, foremost being the availability of cheap fertile land. As the population grew, it was easier to move west where there was abundant land instead of dividing already cultivated areas into smaller and smaller plots. This might have been a factor behind Thomas’ move as well.
A final factor in his decision to leave Ohio might have been the fact that Thomas’ brother in law James Scruby died in 1852,  and James’ wife Phebe died in 1851.  With their deaths Thomas and Emma no longer had family connections in the immediate area.
With his children’s relocation to northwest Indiana, the ongoing migration of other local families to the same area, and the loss of Emma’s family connections in Ohio, Thomas’ desire to move must have been compelling.