His father, Joseph Lockwood (1764-1799), was an innkeeper who died of yellow fever (as did his infant son Cornelius) when Samuel was ten.

[1] The Lockwood boys only remained in that school for a few months before their uncle, Francis Drake, assumed responsibility for them.

They walked across the new state to Kaskaskia, the first capital, but Lockwood returned to the "Little Egypt" region and settled in Carmi, White County, Illinois.

[7][8] Lockwood would move further north following his judicial retirement, and finally settled with his family in Batavia, Kane County, Illinois in 1853.

One of the reasons Lockwood accepted continued appointment from Madison was that it would afford him the time and money to ensure that Illinois would remain a free state, although both Presidents were slave owners.

[12] Early on, Lockwood revised the Illinois Criminal Code, and he resigned after the 1848 Constitution (which he helped draft and supported) reduced the Court's membership to three judges.

In 1837, Lockwood was the only dissenting judge in a case concerning the pre-emption homestead rights of trader Jean Baptiste Beaubien (brought by then fellow Morgan County lawyer Murray McConnell) shortly before the formal closing of Fort Dearborn following the 1833 Treaty of Chicago.

[13] The United States Supreme Court would overrule the other Illinois justices in Wilcox v. Jackson in 1839, before the federal government sold the contested land as the "Fort Dearborn Addition" to the town (which had incorporated as a city in 1837).

[15] In 1844, Lockwood was the only dissenter in the case of abolitionist William Hayes for assisting "Sukey", slave of Andrew Borders who moved to Galesburg, kidnapped her two sons from jail and sold them southward, the remaining judges upholding the transaction.

[20] After the American Civil War, Lockwood also accepted an appointment by Governor Palmer and served on a committee to find a site for an insane asylum in northern Illinois in 1869 (perhaps in part because he was a trustee of the asylum at Jacksonville), at which Mary Todd Lincoln would briefly reside in 1874.,[21] Lockwood died at his home in Batavia in 1874, at age 85.

After a funeral at the Congregational Church, he was interred in the West Batavia cemetery across from his home (and to which he had donated some land to enable a stone fence).

His former home, built in 1849 in the Greek Revival Style and locally known as "Lockwood Hall" and later owned by legislator and public welfare director Rodney Brandon, still exists at 825 Batavia Avenue, off State Route 31.