how many republicans were presidents?
['Abraham Lincoln (1861 – 1865)', 'Ulysses S. Grant (1869 – 1877)', 'Rutherford Birchard Hayes (1877 – 1881)', 'James Abram Garfield (1881 – 1881)', 'Chester Alan Arthur (1881 – 1885)', 'Benjamin Harrison (1889 – 1893)', 'William McKinley Jr. ( 1897 – 1901)']