Answer:
Frank Kudrna was unable to send for his wife and children after he arrived in America because of the onset of the First World War which led to the ports being closed, making it impossible for them to come/ travel.
Explanation:
Frank Kudrna first came to America in December 1912 with the hope of bringing his family into the new home. He had migrated from Sardice, Moravia to America with the hope of starting a new life and hopefully a better one, a better future for his family.
But despite his wants and hopes, the First World War happened which blocked/ prevented any ships from ever plying for immigrants between 1914- 1919. The war closed all major European ports and thus, prevented his wife, Anna, his son Jan and the unborn daughter from following him sooner.