Why was the manifest destiny a issue during war with mexico

How were germany’s and italy’s processes of unification similar ?

Did the spanish settlers and missions have a positive effect on world history? why, what did they do that was positive? why was the treaty of paris (1763) good for the world/world history? did the plymouth colony have a positive effect on world history? why, what did they do that was positive?

Why was lee unable to escape from appomattox? he didnt not have the needed supplies grant had him surrounded davis had ordered him to surrender he was waiting for johnston to bring reinforcements