Yeah, the annexation of Texas. Which is similar to Israel / Palestine in many ways.

The depressing thing is that you don't know that the treaty of Guadalupe Hidalgo was signed 178 years ago, and that territory can be legally ceded by means of peace treaties. The part of Palestine that is considered illegally occupied is the part that lies beyond the 1949 armistice borders and has never been legally ceded to Israel by any treaty.