Contractors, Article 4. Classifications. 7058. (a) A specialty contractor is a contractor whose operations as such are the performance of construction work requiring special skill and whose principal contracting business involves the use of specialized building trades or crafts.
The United States declared war on Germany for many reasons. One of them was the sinking on neutral ships and the lusitania which killed about 148 Americans. This was not the immediate cause, another is propaganda which persuaded public opinion.
The US declared war on April 6, 1917. However, it took time to mobilize soldiers for the army, and US forces were not fully engaged in France until the Spring offensive of 1918. This allowed the US forces to be engaged to the greatest effect along many of the lines of battle.