At the time of his birth, Brattain's father had a 300 acres (120 ha) farm in Linn County east of the Springfield town site.

In 1873, the Brattain family moved east to the Chewaucan River valley, locating south of Paisley, Oregon.

[7] In 1908, the Lake County Examiner began encouraging Brattain to run for a District 21 seat in the Oregon House of Representatives.

They not only citing Brattain’s success in business, but his understanding of key issues relevant to citizens living in District 21 as reason for supporting him.

[8][16][17][18] A month later, Brattain and his fellow legislators were called back to the capitol for a two-day special session before adjourning for the remainder of the biennium.

Governor Frank W. Benson named Brattain as a delegate to the 1909 National Irrigation Congress in Spokane, Washington.

[20][21] A year later, Governor Jay Bowerman names him as delegate to the 1910 National Irrigation Congress, held in Pueblo, Colorado.

[27][28] As a result, he lost the Republican primary to Burdick and Overturf, who went on to win the two District 21 seats in the general election.

[33] After the Nevada–California–Oregon Railway reached Lakeview, Brattain and other Lake County leaders actively engaged in an effort to persuade the railroad to extend its tracks north to Paisley.

During his travels, Brattain crossed the Pacific Ocean, visiting Hawaii, Japan, Korea, China, Philippines, and Singapore.

Brattain then visited countries across Europe including Italy, France, Germany, England, Scotland, Wales, and Ireland before crossing the Atlantic Ocean to New York City.