Democratic Governor Dannel Malloy unveiled the Connecticut Family Preparedness Plan on Wednesday.
He has already clashed with the White House over immigration policy.
The plan is a “step by step” toolkit, in English and Spanish, for parents in case they are detained or deported.
Titled “Family Preparedness Plan: Preparing Your Family for Immigration Enforcement”, it contains advice on legal rights and emergency child guardianship forms.
State officials have created the resource in response to President Trump’s hard-line rhetoric on illegal immigration.
The state’s website says: “We hope that you never have to use your plan, but having one may help reduce the stress of the unexpected.”
Children of undocumented immigrants are legal citizens if they were born in the United States, even if their parents are not.
“We want to make sure that people have a plan in place should immigration action separate their families,” Governor Malloy said.
“It is estimated that there are around 22,000 US citizen children of undocumented immigrant parents living in Connecticut.”
It comes just one month after Governor Malloy traded public blows with the White House over Trump’s immigration policy.
He issued a memo to Connecticut police authorities telling them they “should not take action that is solely to enforce federal immigration law” and that “ICE [Immigration and Customs Enforcement] detainer requests are requests, they are not warrants or orders”.
Press Secretary Sean Spicer in February said it was “troubling” and “concerning” that Mr Malloy “chooses not to follow the duly passed laws of this nation”.
Politico quoted Governor Malloy as saying it felt “really good” to be targeted by the White House.
“You should probably be known by your enemies,” he said.
The governor’s latest document recommends that families decide in advance who will care for their children if they are detained by immigration authorities.
It also contains guidance on what legal rights undocumented immigrants have if ICE officials approach them in person or come to their door.