1) In the late 1700s Poland was split into 3 parts, with the west going to Prussia, the south to Austria and the east to Russia
2)if he arrived in the US between 1908 and 1910 then the parents would not have sent him to the US to avoid war... there was no war duing that time in Russia. However... there were anti-Jewish Pogroms carried out by the Russians 1903-1906http://en.wikipedia.org/wiki/Anti-Jewish_pogroms_in_the_Russ...
3) and 4)have you found him US Census records? If find the following for 1920 census Brooklyn Assembly District 14, Kings, New York
Abraham Kahn 25 Russia imm. 1910 Naturalized 1919
Yetta Kahn 25 Russia imm. 1912
Irving Kahn 3 mths
Abraham was a clerk in a Fur House
and 1930 Bronx NY census
Abraham Kahn 34 imm 1915 Naturalized Clothing salesman
Lillian Kahn 26
Some findings from ship manifests
I find Naturalization info for an Abraham KAHN from 1919 NY and he indicates he arrived on the ship below.... could this be your Abraham KAHN
First Name: Ibe
Last Name: Kahn
Ethnicity: Russia, Hebrew
Last Place of Residence: Curland Bausn
Date of Arrival: Sep 08, 1908
Age at Arrival: 11y Gender: M Marital Status: S
Ship of Travel: Russia
Port of Departure: Libau
NOTE the name on the manifest is actually Abe not Ibe as the transcribers saw it.
He is arriving with his mother and a sister... which of course does not fit the family oral "history" that you have.
Here is an interesting article about the Jewish population of Kurland, Russiahttp://www.jewishgen.org/courland/lipschitz.htm
If you believe the Naturalization papers I have are for your Abraham you can email me direct at firstname.lastname@example.org