The Spanish American War
On March 28, 1893, the Maine Volunteer Militia was designated the Maine National Guard.
When Congress declared war on Spain in April of 1898, the entire National Guard of Maine was mobilized in Augusta. At the time, those units consisted of the 1st and 2nd Maine Infantry Regiments. The 1st Maine Infantry was mustered into Federal service from May 13-November 10, 1898. The unit trained at Camp Thomas in Chickamauga, Georgia but contracted a very dangerous strain of typhoid fever and was sent home and mustered out. Over 40 Soldiers died from this outbreak of disease
The First Maine Heavy Artillery was formed from volunteers from the 1st and 2nd Regiments of Infantry. The First Maine Heavy Artillery departed for Savannah, Georgia in October, 1898, later serving in Havana, Cuba for occupation duty. It returned to the United States and was mustered out of federal service in March, 1899.
The Maine Signal Corps was mustered into service in June, 1898 and served in Cuba during the Santiago campaign until 1899 when it was returned to Augusta and mustered out of service. The Signal Corps gained valuable experience during this deployment.
Read more about that service here.
In 1910, the 1st Infantry was converted to individual companies of Coast Artillery.
There are no Maine Army National Guard units still in service that have campaign honors for the Spanish-American War.