WWI started when the Lusitania sank, when Archduke Ferdinand was assassinated, when Russia contacted Mexico with the Zimmerman telegraph, and when the three merchant ships were attacked and destroyed.
Women were not able to help with military conflicts until 1941 when the Great Depression had ended and factories needed more employees to help make military ammunition in WWII.
Presidential leadership has led us to improve technology today. President John F. Kennedy invented the space race and since then we have created the first space shuttle that has taken us to the moon.