PR for dependent child- Proof of status for US citizen

[vrich]

I am a PR and applying PR for my 1 year old dependent child. What document I give for this proof of status in Canada? He is US citizen and was allowed in Canada on his passport at land border. They didnt stamp or give visitor record. Please help.

 

[armoured]

I am a PR and applying PR for my 1 year old dependent child. What document I give for this proof of status in Canada? He is US citizen and was allowed in Canada on his passport at land border. They didnt stamp or give visitor record. Please help.

See what you can find, if you can't find anything that documents, short letter of explanation that gives best estimate of date/time of entry and which port of entry.