Why did the 1890 census say that the united states no longer had a frontier?

 The correct answer is :  Through the census conducted in 1890 it was announced that the border region of the United States no longer existed and that the census office would no longer seek migration of the population to the western United States, until this year The United States had a settlement border.

valentina tereshkova

soviet cosmonaut valentina tereshkova became the first woman to fly to space when she launched on the vostok 6 mission june 16, 1963. valentina tereshkova was the first woman to go into space. in 1963, she spent almost three days in space and orbited earth 48 times in her space capsule, vostok 6.jan 22, 2018

the manhattan project's indispensable man