Robert Klotz was born in Northampton (now Carbon) county, Pennsylvania, October 27, 1819, and during the winter months attended the public schools, while in the summer months he worked upon the home farm. After he had attained his majority he spent six months in a private school in Easton, desiring to supplement the early educational privileges he had received. He has been a leading factor in public life in this county, a man of much force of character, of strong individuality and of upright principles. In 1843, when twenty- four years of age, he was elected to the office of register and recorder of Carbon county, and in 1846 he was chosen lieutenant of Company K, Second Pennsylvania Infantry Regiment for service in the Mexican war, and afterward became adjutant in the same regiment, under command of Colonel John W. Geary. He was with General Scott in his march to the city of Mexico, and took part in the engagements of Vera Cruz and Cerro Gordo. He afterward participated in other important engagements of the Mexican war, and under command of General Joseph Lane reached the city of Mexico on the 9th of December 1847.

After his return to his home in Mauch Chunk he served for two terms as a member of the Pennsylvania legislature, and in 1854 removed to Kansas in response to an invitation of Governor Reeder of that territory. He aided in making history in that state during the troublous time preceding its admission into the Union, and his influence was widely felt in behalf of good government and against the introduction of slavery. He made his home in Pawnee, and there built the first hotel in western Kansas. He was a member of the historic Topeka constitutional convention, was the first to sign the free state constitution, and after its adoption became the first secretary of state under Governor Robinson's administration. In 1856 he was a member of the celebrated committee of safety to protect the state from invasion, and was appointed brigadier-general of the state troops at Lawrence. He was largely instrumental in making Topeka the capital of Kansas. Following his return to his native state, Major Klotz served as treasurer of Carbon county for one term, and then, with the same patriotic spirit that prompted his defense of his country in the Mexican war, he offered his aid to the government in the Civil war, enlisting at the first call for three months' troops. In 1862 he became colonel of the Nineteenth Pennsylvania Regiment Emergency Troops at the time of Lee's first invasion of Pennsylvania.

The efforts of Major Klotz have been no less effective in promoting the material upbuilding and progress of his community than were his labors in behalf of his country in times of warfare. He became one of the board of managers of the Laughlin and Rand Powder Company of New York, and was financially interested in many other business enterprises of importance. He has been almost continuously in public life since attaining his majority. For a number of years he was a trustee of the Lehigh University. In 1878 he was elected to congress on the Democratic ticket, and two years later was re-elected, and, during his connection with the law-making body of the nation served on several important committees. During the extra session of congress he prepared and introduced a bill for pensioning soldiers of the Mexican war and the families of deceased soldiers. This bill eventually passed both houses and became a law. At one time he was vice-president of the National Association of Mexican Veterans. In 1849 he married Sarah Lentz, a daughter of Colonel John Lentz.