The president’s son-in-law and senior adviser is pressing U.S. Customs and Border Protection and the U.S. Army Corps of Engineers to expedite the process of taking over private land needed for the project as the government seeks to meet Trump’s goal of erecting 450 miles of barriers along the U.S.-Mexico border by the end of 2020. More than 800 filings to seize private property will need to be made in the coming months if the government is going to succeed, officials aid.