Answer :
Theodore Roosevelt, who took office in 1901 and held the position until 1909, is regarded as the first modern President because he considerably increased the executive branch's authority and power.
Who is Theodore Roosevelt?
Theodore Roosevelt Jr., also known as Teddy or by his initials T. R., was an American politician, statesman, soldier, conservationist, naturalist, historian, and writer who served as the 26th president of the United States from 1901 to 1909. He was born on October 27, 1858, and died on January 6, 1919. Prior to that, he served as the 33rd governor of New York from 1899 to 1900, as well as the 25th vice president under President William McKinley from March to September 1901. Upon taking office following McKinley's murder, Roosevelt established himself as the leader of the Republican Party and became a proponent of Progressive and anti-trust measures.
To know more about Theodore Roosevelt check out:
https://brainly.com/question/8210631
#SPJ4