Fifty percent of the signers of the Declaration of Independence were Welsh...as was the captain of the Mayflower. William Penn (founder of Pennsylvania) and Thomas Jefferson. Nine Presidents of the USA were of Welsh descent. You can real more details here.
The Mormon Tabernacle Choir was initially formed from Welsh immigrants from the village of Merthyr Tydfil. Singing harmony in parts as they descended into the coal mines to work was part of their heritage. The choir leader has always been of Welsh descent.
My family arrived in America via the Mayflower and early Jamestown settlers. There's plenty of history there. We don't have to invent a "month" to celebrate a racially focused view of history. Our legacy is the USA.