For which of the following did president theodore roosevelt win the nobel prize in 1906?
for building the panama canal
for the roosevelt corollary
for the open door policy
for the treaty of portsmouth
for the treaty of paris

for the Treaty of Portsmouth

Explanation:

The Treaty of Portsmouth was the Treaty responsible for ending the Russo-Japanese War. President Theodore Roosevelt was the responsible for concluding the negotiation of the Treaty by asking Japan to adopt the open door policy. He was the first US President to win a Nobel prize, he was later followed by Woodrow Wilson, Jimmy Carter and Barack Obama.

by 1880, germany had more rail lines than great britain and russia.